Grant for rims system

[pola0502ds]

Does anyone know how to rotate photos on this site?

Whenever I have that problem, I just rotate the picture in a photo editor and save it before I post.

 

[dstar26t]

Here are a few pics of the grants I've tried. One is made from an asparagus steamer, the other from a Corny Keg. I found the asparagus steamer size was too small for 12 gallon batches but may work for you. I use the asparagus steamer grant as a hopback now. I strive to only allow crystal clear wort to get to the kettle and find that the grant helps greatly.

Asparagus steamer grant/hopback


Corny Keg grant

 

[Foosinho]

organikbrewer, since I've not yet done an all-grain batch, this might be a profoundly ignorant question, but... how do you deal with the trombone when sparging? Do you bypass it at the end of the sparge to drain the MLT? Leave it in place and continue to add water to the MLT until you get your desired pre-boil volume?

 

[fc36]

subscribed

 

[pola0502ds]

How the heck did you cut the corney keg so clean.

 

[dstar26t]

Lazy Susan, sharpy attached to fixed object, angle grinder with cut-off wheel and steady hands
Then a little sand paper.
A corny is perfect because there is an internal ledge at the bottom that the false bottom lays on.

 

[organikbrewer]

Good question, both work. I try to use enough sparge water so that I only use the Trombone, which keeps from jarring the mash bed and letting loose bits of malt. But sometimes I have to open up the bottom valve. I also use an inline screen to catch any particles that may get through.

 

[brewingmeister]

Great info here but I'm not seeing too much on size. I'm looking to add a grant to my system and am looking for the optimal size. Looking to get smooth flow out of the MT without being too much of a heat sink. Organicbrewer's trombone looks to not hold too much liquid, maybe a quart or so and works great for him. dstar26t said his asparagus steamer was too small but by the looks of it is a gallon or so. The corney keg seems to be a pretty big heat sink as well as using the BK as a grant since I am not planning to have all of my wort circulating at one time.

So what would you guys say is the optimal size for a grant? 1qt? 2qt? A gallon? More?

-cheers

 

[organikbrewer]

In my opinion I would say a quart to a half gallon at the most. You don't want to drain your mash of to much wort. Like your saying it will heat sink and drop your mash temp, that's not good unless you reheat it as it goes back into the mash. Also you want to avoid ever letting your mash bed go dry on top, so the larger the grant the more mash water you will need to use. If you look at a grant on a professional system you'll notice the are fairly small, about a 1/4 to a 1/2 barrel. The key is to adjust your pump out put to the runoff of the wort, or install some float switches. I plan on adding float switches to mine in the near future, when I get that all figured out I'll let you know what I did.

 

[chrisdb]

subscribe

 

[cwi]

The objectives of effective wort separation are the removal of unwanted
material while at the same time extracting all the available wort.
Effective wort separation means:-
• Maximising extract recovery.
• Sparging with hot water to extract the maximum amount of soluble extract
(wort).

As far as ways to skin the cat, yes there are different ways to do everything. But 100s of years of study and innovation has been devoted to brewing and modern brewing techniques are used because they are the best for quality and extract. Ideally you should have a very shallow tun with lots of surface area for the false bottom. For home brewers that is hard to do, so by using a trombone setup you are revealing (relieving is what you meant, I think) the weight that is pressing upon the false bottom. I brewed a Saison yesterday and in a 1hr runoff I extracted 95% of the available extract. The proof is in the pudding.

Compaction is related to runoff speed, but also the quality of the grind, surface area of the false bottom and the depth of the mash bed.

If you want to be taken seriously by any engineer types on here, you will need to stop talking about how your 'trombone' (which functions like a weir) is relieving the weight on the grain bed and false bottom. The pressure is being relieved, but only at the outflow of at the top of the trombone. As long as the grain bed is already submerged, the static weight on the false bottom cannot be decreased, it can only be increased by the increasing the outflow rate. The 'trombone' merely acts as liquid level regulator ensuring liquid level in the tun is at least as high as the outflow. With the trombone, outflow rate is a function of inflow rate and the height (pressure) differential of the outflow and tun level. This same effect can be achieved with a pressure gauge in combination with a valve and/or pump.

It is humorous that you keep talking about modern practices (mostly about efficiency, though), and then tell guys who are using pressure gauges and sensors tied to automatic pump controls to precisely monitor the pressure differential being generated during lautering, that they are doing it wrong. They are doing it the modern way, you are the Luddite in this case. Not that yours isn't an effective way to control compaction, it is just an old school method. I have seen the term "swan neck" used to describe it.

You have a thing for efficiency, regardless of time, and that is your personal bent. As a 'professional' doling out advice to us lowly homebrewers, why not give a solution that meets the requirement (less time) without decreasing quality, instead of preaching your mantra of more time and maximum efficiency. It can be done. In fact, the quality of the first half of the wort is of higher quality than the last half. So if a home brewer wants to 'no sparge', or sparge as fast as practicable, it would seem he is only costing himself a few dollars in grain. On plus side, he is increasing his wort quality, and allowing the wife to get back to nagging him that much faster to boot.

In reality, flirting with max efficiency like you do, is flirting with over extraction. Most homebrewers would gladly trade some efficiency (a few bucks) for some margin of safety, large scale brewers would not. I am sure there are many modern techniques used in large breweries that are applicable to homebrewing, maximizing efficiency isn't one of them.

As for grant size being a heat sink issue, how about using some insulation? That is something your all copper trombone could use. Most posters here mentioned using a RIMS anyway, so initial heating is not an issue. As long as the grant is reasonably squat, it won't lose that much heat once heated. If the grant is only used during the sparge, who cares if a bit of heat is lost to the grant on the way to the kettle?

 

[millaj92]

So I've read this whole thread and amazingly enough my question is still unanswered. I understand the grant and I get the reasons. I don't disagree with any of that. My question is, is it better or worse than my setup? When I recirc or sparge, I open the output valve on my MLT all the way, which goes into a pump, there's a valve on the output of the pump before going into the HE and back into the top of the grain bed. I just barely open the valve past the pump. In my head, the restricted pump output blocks the flow into the pump from going any faster than that, which in itself doesn't let the wort drain very quickly and also accomplishes the whole make the grain bed weightless and keep negative pressure on the underside of the false bottom. Also, there is no chance for this mysterious and elusive HSA because it's all a closed-loop system. I have decided this is better than using a grant. Before I get attacked, I am of course open to the possibility that I am wrong since I am not all-knowing and If I am wrong, please enlighten me.

 

[Bugaboo]

I'm also on the fence about having to use a grant. Seems to me that if your pump output is set at nearly the same rate as your lauter rate then there would be no worry about the suction of the pump compacting the grainbed. Plus you would have to adjust your pump output even with a grant.

The weir looks like a good project. I'd put compression fitting on the 3/4 in pipe so you could skip using the orings, but that would make it a bit more expensive. I've never used one so I'm not sure if that would work. Could also attach the whole trombone on a compression fitting on the mlt outlet and just swing it away from an upright position to match the top of the grain level.

P.S. Great thread! Crappy tone

 

[cwi]

I just barely open the valve past the pump. In my head, the restricted pump output blocks the flow into the pump from going any faster than that, which in itself doesn't let the wort drain very quickly and also accomplishes the whole make the grain bed weightless and keep negative pressure on the underside of the false bottom. Also, there is no chance for this mysterious and elusive HSA because it's all a closed-loop system. I have decided this is better than using a grant. Before I get attacked, I am of course open to the possibility that I am wrong since I am not all-knowing and If I am wrong, please enlighten me.

The "just barely open the valve" and "doesn't let the wort drain very quickly" parts is where you missed the point of the grant described here (one with an outlet almost to the level of the mash, or a guage to directly measure pressure).

The trombone or gauge type grant setups guarantees that the flow doesn't create too much suction or, at the extreme, allow the false bottom to go dry. Adjusting the valves so that something is "barely" or "not very quickly" doing whatever, is not reliable or repeatable. Now matter how slow you set your valve to flow, there is still a chance of compaction if the mash is very "sticky". The grant systems described here are either self adjusting (trombone, swan neck), or in the case of using just a pressure guage, directly measure the compaction pressures and allow manual or automatic control.

With your method, if the mash is becoming stuck, your "barely open" valve setting will continue to drain causing increasing compaction pressures and eventually a dry false bottom.

One other issue brought up occasionally is product "shear" caused by throttling the outflow of centrifugal pumps. The popular March pumps are turning 3500rpm, whether you have it throttled or not. Because of this, some only use a grant as a means to avoid whipping their product continuously. Instead they cycle the pump on occasionally or automatically whenever the grant fills. The flow into the grant can be done as described above, or by manual fiddling with the valves.

 

[cwi]

I'm also on the fence about having to use a grant. Seems to me that if your pump output is set at nearly the same rate as your lauter rate then there would be no worry about the suction of the pump compacting the grainbed. Plus you would have to adjust your pump output even with a grant.

Your assumptions only hold true if the inflow dictates outflow. However, the the grain bed dictates outflow, not inflow. If the fixed outflow rate is too high, or bed restriction increases during the sparge, suction is created and adds compaction forces to the bed, further restricting outflow (vicious loop). The trombone auto-compensates for this, and a gauge would allow you to see what is happening and adjust.

RE: cycling/adjusting pump- that is why the guy who got the beatdown originally came to the thread to find. He was looking to see what type of float switch guys were using on their grants to auto trigger pumps periodically when the grant was full.

Even manually adjusting the pump output for the grant does have an advantage in that it is no longer as critical an issue. The only two things that can happen are an overflowing or an empty grant, but at least the mash won't stick. So I guess it depends how worried you are about a stuck mash.

 

[yinzer2]

cwi,

Let say that I have two setups with the same flow rate.

System one had a trombone, swan neck, whatever. It has a 1/2" ball valve that is wide open feeding a pathway no smaller than 1/2 in diameter. The flow-rate is limited by the hight of the arch at the top of the said device.

System two has outflow that is reduced only buy reducing the diameter of the exit value thus reducing the diameter of the exit.


The second system would have liquid traveling at a greater speed. Does this effect grain compaction? I would imagine not, especially with a false bottom. But I just had to ask.

 

[cwi]

cwi,

Let say that I have two setups with the same flow rate.

System one had a trombone, swan neck, whatever. It has a 1/2" ball valve that is wide open feeding a pathway no smaller than 1/2 in diameter. The flow-rate is limited by the hight of the arch at the top of the said device.

System two has outflow that is reduced only buy reducing the diameter of the exit value thus reducing the diameter of the exit.

The second system would have liquid traveling at a greater speed. Does this effect grain compaction? I would imagine not, especially with a false bottom. But I just had to ask.

Your setup and question is a little puzzling. If I had to guess, you have a false bottom, and use a valve to control lautering rates. If you are looking for some solid ground to stand on to support this approach, you may be out of luck. It's only "pros" may be cost and simplicity, and perhaps that these other approaches are overkill. However, I would say that a prerequisite to claiming these devices are overkill is personally experiencing a stuck mash.

The short answer is that the velocity of the wort at the valve restriction has no direct impact on the compaction of the grain bed up-valve. This is not because a false bottom is used, or even particularly mitigated by it. In your scenario, given identical flow rates, the wort within the bed will have the exact same flow rate in both cases. If there is an elevation gain post valve, once past the "pooling point", the velocity in the hose will the same in both cases also. However, things are not that simple in the real world. One cannot assume that the grain bed remains static throughout lautering. In fact, it is almost guaranteed not to remain static.

The long answer gets very complicated, especially since I will provide some analysis and background info on what I am basing my positions on.

Caveats: This should be basically correct, but I may have missed something; not correctly reasoned some detail; or not adequately explained some part. The effect of a pump was not considered in this analysis, mainly due to them only exacerbating the situation and not mitigating any of the issues. A pump simply increases the maximum negative relative pressure (suction) that can occur at the bottom of the bed. The swan neck is a type of weir with a riser pipe drain. There should be some papers online, written by real scientists, if you google it.

Here is a first crack at it:

What causes compaction is the force of the moving wort (throughput) on the restriction/resistance within the bed, and/or dewatering of the grain bed. As flow increases, the downward force on the bed increases. A special (bad) case is when the restriction in the upper part of the bed is higher than in the lower part of the bed . In this case, if the outflow exceeds the recharge rate through the upper bed, a localized negative pressure differential (relative vacuum) is created by the lower bed that exerts a pulling force on the upper bed. Dewatering is a worst case scenario of the above where air infiltrates the lower bed, causing the lower bed to run dry. At that point, the force of the entire mass of the upper bed (grain and wort) is exerted on the lower bed, instead of the much smaller force of the bouyed upper grain bed (grain less the mass of the water it displaces).

What the swan necks and pressure gauge/valve combos can do that a cracked valve cannot is to automatically regulate the compaction force applied to a bed due to throughput. This is achieved by guaranteeing that the reduced pressure at the outflow does not go below a set pressure level.

With the swan neck, the flow is determined by controlling the pressure. A fixed pressure set point is established based on the height differential of the tun level and neck apex (tube diameter is a factor as well, more on that later). Physics takes care of controlling/maintaining the pressure. This both guarantees the bed can't dewater, and also regulates flow, in a sense, as a side effect. If the bed becomes more restrictive, the pressure at the apex drops, and the flow decreases. This brings the pressure back to the set point. The flow is variable according to how restrictive, or not, the bed becomes, but the pressure exerted on/through the grain bed remains the same.

With a gauge and a valve, the pressure is determined by controlling the flow. The pressure gauge provides an indicator of the force being applied to the bed, and also if the bed is becoming dewatered. A set point is determined (just as with a swan neck), and is controlled by increasing or decreasing flow directly. What a pressure gauge can do that the swan neck can't, is maximize flow by having a larger flow capacity available that does not adversely affect control of the system.

This is due to the swan neck having a flow limit of sorts built in, on purpose. The diameter of the tubing is part of the pressure set point equation. As flow increases, the pressure at the apex also increases, reducing the differential and limiting flow. Bigger tubing can allow for more flow while maintaining the same pressure set point, but also makes establishing the pressure set point more problematic, since the differential range will be smaller, among other things.

With a valve only, the above systems can be mimiced, but the only feedback indicator available is the rate and change in outflow, whose variability decreases as the valve restriction decreases. This is not a very precise method, and may actually be made worse by a false bottom, since the buffer created by the dead space below the false bottom can hide a dewatering event before any noticeable (by a human) reduction in flow is observed. The worst case is the dead space running dry. This is an issue with manifolds and bazookas also, but a bazooka/manifold provides more immediate feedback since there is less buffering of the output, which allows faster detection. However, a false bottom does a better job of spreading the flow over the entire bottom of the bed. This helps prevent localized compaction from occurring which can lead to a clogged manifold/screen.

Setting a valve to an initial flow that seems "'just 'bout right" and then walking away is the simplest method, but provides virtually no protection against a compacted grain bed.

Decide how much chance you think you have of getting a stuck mash; how much you want to avoid one; and pick your poison.

 

[millaj92]

The "just barely open the valve" and "doesn't let the wort drain very quickly" parts is where you missed the point of the grant described here (one with an outlet almost to the level of the mash, or a guage to directly measure pressure).

The trombone or gauge type grant setups guarantees that the flow doesn't create too much suction or, at the extreme, allow the false bottom to go dry. Adjusting the valves so that something is "barely" or "not very quickly" doing whatever, is not reliable or repeatable. Now matter how slow you set your valve to flow, there is still a chance of compaction if the mash is very "sticky". The grant systems described here are either self adjusting (trombone, swan neck), or in the case of using just a pressure guage, directly measure the compaction pressures and allow manual or automatic control.

With your method, if the mash is becoming stuck, your "barely open" valve setting will continue to drain causing increasing compaction pressures and eventually a dry false bottom.

One other issue brought up occasionally is product "shear" caused by throttling the outflow of centrifugal pumps. The popular March pumps are turning 3500rpm, whether you have it throttled or not. Because of this, some only use a grant as a means to avoid whipping their product continuously. Instead they cycle the pump on occasionally or automatically whenever the grant fills. The flow into the grant can be done as described above, or by manual fiddling with the valves.

Like I said, I understand the physics of and reason behind having a grant or a "trombone." To clarify, I am not worried about a stuck mash. I am not talking about just barely opening a valve and seeing what happens. I am experienced therefore I have learned what kind of flow rate I can get out of my MLT with different types of grain in it. I know how fast I can go without getting a stuck mash. When I recirc and sparge, I open the valve on the output of the pump so as to effectively let the MLT drain about half speed of what I know it will do without sticking. As far as things that concern pump life, I didn't ask about that. And by the way, you can still get a stuck mash WITH a grant.

 

[millaj92]

Your setup and question is a little puzzling. If I had to guess, you have a false bottom, and use a valve to control lautering rates. If you are looking for some solid ground to stand on to support this approach, you may be out of luck. It's only "pros" may be cost and simplicity, and perhaps that these other approaches are overkill. However, I would say that a prerequisite to claiming these devices are overkill is personally experiencing a stuck mash.

The quick answer is that the velocity of the wort at the valve restriction has no direct impact on the compaction of the grain bed up-valve. This is not because a false bottom is used, or even particularly mitigated by it. In your scenario, given identical flow rates, the wort within the bed will have the exact same flow rate in both cases. If there is an elevation gain post valve, once past the "pooling point", the velocity in the hose will the same in both cases also. However, things are not that simple in the real world. One cannot assume that the grain bed remains static throughout lautering. In fact, it is almost guaranteed not to remain static.

The long answer gets very complicated, especially since I will provide some analysis and background info on what I am basing my positions on.

Caveats: This should be basically correct, but I may have missed something; not correctly reasoned some detail; or not adequately explained some part. The effect of a pump was not considered in this analysis, mainly due to them only exacerbating the situation and not mitigating any of the issues. A pump simply increases the maximum negative relative pressure (suction) that can occur at the bottom of the bed. The swan neck is a type of weir with a riser pipe drain. There should be some papers online, written by real scientists, if you google it.

Here is a first crack at it:

What causes compaction is the force of the moving wort (throughput) on the restriction/resistance within the bed, and/or dewatering of the grain bed. As flow increases, the downward force on the bed increases. A special (bad) case is when the restriction in the upper part of the bed is higher than in the lower part of the bed . In this case, if the outflow exceeds the recharge rate through the upper bed, a localized negative pressure differential (relative vacuum) is created by the lower bed that exerts a pulling force on the upper bed. Dewatering is a worst case scenario of the above where air infiltrates the lower bed, causing the lower bed to run dry. At that point, the force of the entire mass of the upper bed (grain and wort) is exerted on the lower bed, instead of the much smaller force of the bouyed upper grain bed (grain less the mass of the water it displaces).

What the swan necks and pressure gauge/valve combos can do that a cracked valve cannot is to automatically regulate the compaction force applied to bed due to throughput. This is achieved by guaranteeing that the reduced pressure at the outflow does not go below a set pressure level.

With the swan neck, the flow is determined by the controlling pressure. A fixed pressure set point is established based on the height differential of the tun level and neck apex (tube diameter is a factor as well, more on that later). Physics takes care of controlling/maintaining the pressure. This both guarantees the bed can't dewater, and also regulates flow, in a sense, as a side effect. If the bed becomes more restrictive, the pressure at the apex drops, and the flow decreases. This brings the pressure back to the set point. The flow is variable according to how restrictive, or not, the bed becomes, but the pressure exerted on/through the grain bed remains the same.

With a gauge and a valve, the pressure is determined by controlling the flow. The pressure gauge provides an indicator of the force being applied to the bed, and also if the bed is becoming dewatered. A set point is determined (just as with a swan neck), and is controlled by increasing or decreasing flow directly. What a pressure gauge can do that the swan neck can't, is maximize flow by having a larger flow capacity available that does not adversely affect control of the system.

This is due to the swan neck having a flow limit of sorts built in, on purpose. The diameter of the tubing is part of the pressure set point equation. As flow increases, the pressure at the apex also increases, reducing the differential and limiting flow. Bigger tubing can allow for more flow while maintaining the same pressure set point, but also makes establishing the pressure set point more problematic, since the differential range will be smaller, among other things.

With a valve only, the above systems can be mimiced, but the only feedback indicator available is the rate and change in outflow, whose variability decreases as the valve restriction decreases. This is not a very precise method, and may actually be made worse by a false bottom, since the buffer created by the dead space below the false bottom can hide a dewatering event before any noticeable (by a human) reduction in flow is observed. The worst case is the dead space running dry. This is an issue with manifolds and bazookas also, but a bazooka/manifold provides more immediate feedback since there is less buffering of the output, which allows faster detection. However, a false bottom does a better job of spreading the flow over the entire bottom of the bed. This helps prevent localized compaction from occurring which can lead to a clogged manifold/screen.

Setting a valve to an initial flow that seems "'just 'bout right" and then walking away is the simplest method, but provides virtually no protection against a compacted grain bed.

Decide how much chance you think you have of getting a stuck mash; how much you want to avoid one; and pick your poison.

I don't believe you completely understand back pressure. Just my opinion but maybe you need to learn more about fluid dynamics. And just for the record, I never "just walk away" from a sparge.

 

[cwi]

As far as things that concern pump life, I didn't ask about that.

And I never commented on pump life.
I commented on product "shear", which is letting a 3500 rpm egg beater whip away on your product (wort) at <10% flow rates for an hour. It might be a non-issue, but I would rather avoid it than not.

And by the way, you can still get a stuck mash WITH a grant.

I never said you couldn't, but it is much harder. If the initial pressure differential is set within reason, the flow will self regulate. This is not the case when setting the flow by partially opening a ball valve, especially when it is after a pump.

I don't believe you completely understand back pressure. Just my opinion but maybe you need to learn more about fluid dynamics.

I am not sure which "back pressure" you are talking about, since I never mentioned it, but the only relevant pressure I see in your setup is the pressure (your "back pressure"?) created by the pump (and gravity depending on pump location) on the "flow" valve. This pump created pressure is what can create SUCTION on the grain bed when the bed restricts throughput. This suction is only limited by the inlet suction force of the pump, since the flow valve will let fluid pass.

Your method seems to describe sparging so slowly that the system is quasi-hydrostatic. The relevant quasi-hydrostatic pressure (your back pressure?) is still only at the output restriction, since everywhere else has a continuous pressure gradient with no localized boundary layers. This would prevent excessive flows/compaction/pressure differentials, etc., but only because the system has been simplified to a quasi-static one (at the expense of attainable flow rate).

The purpose of the swan neck or pressure feedback is to set an appropriate pressure limit, and let the system adjust the flow dynamically. This allows faster sparging while providing protection against compaction that isn't possible if a fixed flow rate is set with a ball valve.

Regardless, I am fairly certain my understanding of fluid dynamics (and statics) is complete enough for this system. I could repost the analysis using a bunch of equations with greek symbols, ', and 1 & 2 sub and superscripts everywhere; but I don't think it would be of any benefit.
You say you understand the physics; question my grasp of fluid dynamics; but you haven't cited which part of my analysis is wrong. Please explain where you think I am incorrect, and I will reexamine it.

And just for the record, I never "just walk away" from a sparge.

I never stated that you did "just walk away" after starting the sparge.
So, you would fit into the prior use case where the flow is varied manually by observing the flow and rate of change of the flow.

You do realize that the post you quoted was not directed at you, but to another poster who wanted an explanation to a hypothetical case he presented? Maybe I should have quoted Ron Popeil and used "Set it, and forget it!" instead. It was merely a quick way of saying that the valve position is left fixed while sparging.

 

[jgln]

Shoot. I thought this thread was going to be about how to receive a gift of money from the government to buy a RIMS system. Guess i'll have to fund my own now.

Me too and figuring I wouldn't be surprised.

 

[CoryNJ]

My purpose for a Grant does not even concern a stuck sparge. I have a direct fired RIMS system and I have repeatedly crushed my false bottoms. Even when slowing the output flow to a crawl. The false bottom I use is the Adventures in Homebrewing PICO style false bottom.
It looks like this: http://www.homebrewing.org/Stainless-Steel-PICO-style-keg-kettle-false-bottom-wsupports_p_1010.html

When I say crushed, I mean crushed like a pancake. I just could not believe the amount of pressure that was being projected onto the false bottom. I use two pumps. One is a March 809 and the other is a March 815. Nothing out of the ordinary there. I have tried changing hose diameter, pump positioning, re positioning pickup tubes. Everything. A grant seems to be the only option to fix my current dilemma.

 

[mors]

My purpose for a Grant does not even concern a stuck sparge. I have a direct fired RIMS system and I have repeatedly crushed my false bottoms. Even when slowing the output flow to a crawl. The false bottom I use is the Adventures in Homebrewing PICO style false bottom.
It looks like this: http://www.homebrewing.org/Stainless-Steel-PICO-style-keg-kettle-false-bottom-wsupports_p_1010.html

When I say crushed, I mean crushed like a pancake. I just could not believe the amount of pressure that was being projected onto the false bottom. I use two pumps. One is a March 809 and the other is a March 815. Nothing out of the ordinary there. I have tried changing hose diameter, pump positioning, re positioning pickup tubes. Everything. A grant seems to be the only option to fix my current dilemma.

When your false bottom collapses that is due to the pressure being exerted on it. I would say that after it collapses you have a stuck mash/sparge. either way the grant would solve that issue (since they are the same issue).

 

[mors]

also... woot year old quote ;-)