Water Treatment with BIAB and using too many Campden tablets.

[BitterSweetBrews]

I have a couple quick water questions:

1. I use RO water. When building up my water for 3 vessel brewing I use different additions for strike and sparge water based on either Beersmith or BrunWater. I have pretty much converted to mostly BIAB. I am wondering how that changes the way I add salts. Are there things I should shy away from since I am adding all the water at once?

2. I always throw a campden tablet into my strike and sparge water as insurance against chloramine. Usually this is around 10 gallons. I have been gathering RO water in 5 gallon buckets for this weekends big brew, so far 30 gallons. Without really thinking i threw a campden tablet into each bucket. Is that going to be too much and have any bad effects? Doesn't sodium metabisulfate retard fermentation?

Thanks,
Tim

 

[mabrungard]

If you're using RO water, the machine is likely removing all the disinfectant from the water prior to passing through the RO membrane. You shouldn't need the campden for disinfectant removal at that point. However, having a bit of metabisulfite in your water does protect from malt oxidation in the mashing and boiling stages. That's good for some malt focused styles, but I find that it does change the flavor of the beer in other styles. This is particularly true when the grist has any roast grain in it.

SMB is destroyed in the boil, so you don't need to worry about it affecting fermentation.

 

[ajdelange]

Yes but it will probably all be converted to SO2 which will either reduce something (and become SO4--) or be driven off as a gas by heat. The thing I would worry about is that it can also form adducts some of which are pretty nasty tasting. In the usual use of it for clearing out chloramine it is largely consumed by the reaction with chloramine and with it being oxidized and driven off with heat you have nothing to worry about. And you probably have nothing to worry about here. After all vintners throw in 1 tablet/gal of their finished wine and it doesn't do much there (unless you are sensitive to it).

 

[mabrungard]

I agree with AJ about the potential for SMB to form adducts and the potential for off flavor. I do recommend adding SMB only to the degree actually needed and not to overdose with that compound.

 

[BitterSweetBrews]

Thanks for the reply. I think I will dump half of the water I added it to and mix it with unaltered RO water.

 

[Silver_Is_Money]

The commonly accepted standard approach to chlorine and chloramine removal is to add 1 crushed Campden tablet for every 20 gallons of water to be treated. This quantity of Campden is likely somewhat of an overkill for most water treatment situations.

 

[ajdelange]

Thanks for the reply. I think I will dump half of the water I added it to and mix it with unaltered RO water.

That's easy enough to do. You could also add a bit of hydrogen peroxide but you'd need to calculate the amount and that's doubtless more bother than just dumping.

The commonly accepted standard approach to chlorine and chloramine removal is to add 1 crushed Campden tablet for every 20 gallons of water to be treated. This quantity of Campden is likely somewhat of an overkill for most water treatment situations.

That dose was calculated to clear the maximum allowable chloramine level. Even if a user's actual chloramine level is substantially less than this the amount of SO2 introduced is not likely to be a problem. I recommend finding out how much chloramine is actually dosed and adjusting the metabite accordingly. There is a Sticky here with the necessary data. Or one can 'titrate' the metabite adding it until an agitated sample of the water no longer smells of chlorine.

 

[Buckeye_Hydro]

What carbon filter(s) are you using before the water reaches your RO membrane?

Russ

 

[BitterSweetBrews]

What carbon filter(s) are you using before the water reaches your RO membrane?

Russ

I am not actually sure exactly what my filters have in them without looking it up, but I believe I have two carbon pre-filters.

Water enters my house through a whole house carbon filter (changed 1 month ago) then a Morton water softener. These are before the 5 stage RO system which I have split to a couple fridges and a tube to my brewing area. I use an aquarium float valve on a lid to fill my HLT or 5 gallon buckets. The RO filter stages are: PPF, GAC, CTO, pump, then the RO Membrane, then a T33 carbon filter and pressure tank. I just checked my TDS after the RO and it was 21 (as I recall it starts out at around 315). This is a cheap import system from Costway.com. I believe it is rated at 50 gallons per day. I paid somewhere around $90 for it on sale with free shipping about 18 months ago. They now sell it for $118 with free shipping.

Can I change to a 100GPD membrane when I need to replace the filters and if I do are there consequences?

If I use tap water I run it through a carbon filter from a Scottsman commercial ice/water machine.

Following is a picture of my RO system:

 

[Buckeye_Hydro]

Assuming you are on city of Omaha water, they do indeed use chloramines. Your existing carbon prefilters are allowing nearly all of that through. Suggestion: use a 1 micron sediment filter followed by two Chloraguard carbon blocks. Get rid of the GAC cartridge and the CTO cartridge.

Russ

 

[BitterSweetBrews]

Assuming you are on city of Omaha water, they do indeed use chloramines. Your existing carbon prefilters are allowing nearly all of that through. Suggestion: use a 1 micron sediment filter followed by two Chloraguard carbon blocks. Get rid of the GAC cartridge and the CTO cartridge.

Russ

Thanks for the advice Russ.

Yes I am on Omaha water, from our West, Platte River water treatment plant. We have three plants in different areas of the county and you can actually be on any of them as they are interconnected. Our water utility company told me we are normally on this one when I called to see which of our three water reports I should use. Once in a while I use 50/50 RO/City water and need to know this.

It is about time to change out the filters so I will definitely consider this. Would you mind explaining what the difference is between the CTO and GAC filters and the carbon block ones. Is it just finer filtering? Would it be detrimental to go for a membrane that can process more water per day or are they larger holes that will allow more particulates through? Would the different filters offset this? Would waste water use go up a lot? I haven't really had a problem with output up to now, as long as I plan brew day water collections in advance and do it over night so it doesn't affect my ability to get water for my morning coffee LOL

Thanks,
Tim

 

[Buckeye_Hydro]

Hi Tim.

Carbon blocks vs GAC: When used as a prefilter to an RO, GAC is ancient technology. It is very inexpensive for vendors to supply, and that's why they still use it - they know most buyers don't know the difference. GAC is relatively ineffective relative to the newer technology - carbon blocks. Blocks are made of PAC rather than GAC. Essentially the same material, but ground to a powder so there is much higher surface area, and far superior performance.

Now, there are low-end blocks, and higher quality blocks, and then there better blocks yet (those intended to treat chloramines). "CTO" blocks are typically 5 micron or larger, and are fairly run of the mill blocks. High end chloramine blocks are made from a special type of PAC, called catalytic PAC - it is a much faster acting PAC, which is needed for chloramine treatment.

In general, the finer (lower) the micron rating on the block, the more carbon the block contains and the higher its capacity.

Regarding the membrane - all our membranes up to an including the 100 gpd are spec'ed at 98% or higher rejection. "Waste water" stays at the same ratio relative to the amount of purified water produced, but it is just produced faster.

Feel free to call in if you want to discuss.

Russ
513-312-2343

 

[mabrungard]

The issue of chloramine removal will be compounded if your membrane capacity is increased. The increased membrane flow and waste flow will overwhelm the capacity of the activated carbon cartridge to remove chloramine. As mentioned, a carbon block is a better technology and it packs more carbon into the small cartridge and that improves chlorine and chloramines removal. But there is NO substitute for enhancing chloramines removal other than drastically increasing the residence time in the filter by either getting more or bigger filters or reducing the overall flow rate through the filters. Getting a higher capacity membrane and accompanying waste restrictor will be exactly the wrong thing to do.

While chloramines-enhanced carbon blocks will help, their improvement is marginal at best. A standard 10" carbon block filter can easily remove chlorine when the flow rate through the filter is up to 1 gal/min. That allowable rate drops to 0.1 gal/min when chloramines removal is required. The enhanced carbon blocks only slightly improve that performance to maybe 0.2 gal/min. Don't go thinking that the enhanced blocks improve the removal to that for chlorine.

Don't aim for a higher membrane capacity since its a red-herring. 100 gal/day is still only 9 ounces per minute. It will take a while to fill any vessel with a typical brewing volume of water. A better use of your money is to get a bigger storage tank or vessel so that you can instantly draw off the volume you need.

 

[Buckeye_Hydro]

Martin - those flow rates you mention are well below spec for the latest/greatest 1025 chloramine blocks. Performance of these blocks is far superior to standard carbon blocks. Also - recall that a 100 gpd membrane @ 20% recovery has feedwater flow at only 0.35 gpm.

0.2 gpm flow through a 1025 carbon block is again, well below typical use and factory specs.

Russ

 

[BitterSweetBrews]

Thanks Russ and Martin for the input. This is great information. I do have one more question regarding chloramine. Without sounding flippant, if that is the biggest or only real benefit of using the $20 each carbon block filters, replacing the "Old Technology" filters that remove 95.%+ of particulates, why wouldn't I just use a 10 cent campden tablet to get rid of the chloramine, instead an additional $40 worth of filters?

From the membrane standpoint I would like a faster flow but I do have a 2.5 gallon tank that keeps ahead of usage unless I am collecting brewing water. I don't want to overload the filtering capacity. So unless I buy a matched set of filters/membrane I will probably leave it as is at 50GPD. When I do collect brewing water I just put a float in my HLT and it fills to 11 gallons in a couple hours. The pump in my system, in front of the membrane, really helps with this and with keeping the serving pressure up in my fridge 25 feet away.

 

[Buckeye_Hydro]

Remember that the filters you pay for also treat the water going to your fridge, and that they are good for months. No need to match the prefilters to the membrane. If you have chloramines, you should be using the chloramine carbon blocks.

If you're making 11 gallons in 2 hours, something is amiss. That's 5.5 gallons in one hour, or 132 gallons per day. Even if your pump raises your pressure to 90 psi, you wouldn't see that sort of production out of a 50 gpd membrane. See http://www.buckeyehydro.com/calculator/

Russ

 

[mabrungard]

0.2 gpm flow through a 1025 carbon block is again, well below typical use and factory specs.

Russ, an important consideration is that there are carbon filter users that are unaware that even that enhanced carbon will not remove all chloramines when the flow rate through the filter is too high. The typical hose bib and house piping can deliver around 5 gpm and if a brewer hooks up a standard 2.5" x 10" filter and cartridge, they can easily exceed the removal capability of a carbon filter. Some pretty serious throttling of the flow is necessary.

Back when I lived in Tallahassee, I used a 2.5" x 10" filter unit that I inserted a 1/16" diameter flow orifice into the supply line to limit the flow to 1 gpm. Tallahassee uses only chlorine for disinfection. That worked fine in that case as I often confirmed that the unit was removing all chlorine by testing the output water with a Total Chlorine test kit.

If an unscrupulous manufacturer were to scrimp on the amount of enhanced carbon in those carbon cartridges, it would certainly mean that the chloramines removal capability would be compromised in RO systems somewhere under 100 gpd. For anyone reading this, I do state that I believe that Russ is a principled vendor and he does strive to do right by his customers. Sadly, there are WAY TOO MANY water system vendors and suppliers that do NOT adhere to much in the way of ethics or performance. Caveat Emptor, to the extreme, for anyone buying equipment or replacement parts. There are actually snake oil salespersons out there in the water treatment business. That is why I have to caution any RO system user to employ caution when their water supply has chloramines in it and their RO unit can produce more than about 50 to 75 gpd. The typical 2.5" by 10" carbon filter could easily be overwhelmed and that will seriously affect membrane life.

An important take away for anyone with one of those compact RO systems with the tiny in-line carbon filters...those small carbon filters have NO CHANCE of effectively removing chloramines from your water supply prior to passing through your membrane. I will state categorically, those systems should not be used unless their membrane capacity is well below 50 gpd. For those of you that do have a system like that, its easy enough to retrofit a larger carbon filter housing into your system. I suggest you contact Russ ASAP.

 

[Buckeye_Hydro]

I cringe when I see people routing a 1/2" pipe to a 10" x 2.5" filter, and then they connect a 1/2" outlet pipe... and they assume that little 10" x 2.5" filter is doing the job. I see it all the time.

 

[BitterSweetBrews]

Remember that the filters you pay for also treat the water going to your fridge, and that they are good for months. No need to match the prefilters to the membrane. If you have chloramines, you should be using the chloramine carbon blocks.

If you're making 11 gallons in 2 hours, something is amiss. That's 5.5 gallons in one hour, or 132 gallons per day. Even if your pump raises your pressure to 90 psi, you wouldn't see that sort of production out of a 50 gpd membrane. See http://www.buckeyehydro.com/calculator/

Russ

The 11 gallons in a couple hours wasn't a correct statement. If I am collecting on a resting system I can get 4-5 gallons in an hour, but that is including the 2-3 gallons that was in the tank. Once it is down to a trickle I would bet it is closer to no more than a couple gallons an hour. If I am collecting in my 50 liter HLT keggle (with the float valve I collect about 11 gallons) I just start it before going to bed or work and let it go all night/day when no one is around to notice. I have never timed it, it is just done when I get back to it.