Unorthodox mash setup, would this matter?

If anybody can help me with some thoughts/comments on my set up I would be grateful. Its all a bit odd......

My mash is a 500L dairy bulk tank. Its like an enormous steel cylinder laying horizontally, but just the bottom half, with a cooling /heating jacket and steel covers. I can control the mash temp to 67C pretty exactly by preheating the tank and lots of insulation. The tank is so huge the grain cover on the bottom is never deep (maybe 8 inches for 31kg for 150L brew but its 1.5m by 1.5m!).

Its a nightmare to get the grain out afterwards but the potential for volume is urging me on and its a beautiful tank and needs to brew beer.

It drains to a 2inch drain at one end which I flood first and then cover with steel gauze. I sparge at 80C with a hosepipe with a spray end, its not very elegant nor gentle nor a very even sparge, its more like drain, flood and a slow drain.

It all seems to work ok but I wonder what effect it might have on flavours?

The SGs are fine (1040). My beers are tasty enough (well I'm delighted). Being hyper critical they are dull. I want to make Goose Island IPA which you could never say was dull. I don't think there is any problems at the boiling hop ferment end. I wonder about the mash set-up, maybe I need a false bottom and a proper sparge arm? There must be so much going on in the mash that should be controlled for the really good flavours?

Comments?

Size of the tank leads me to believe that you might want to read up on batch sparging, search function will help with that one.

Also, you might want do do some efficiency calculations to see how well the system is working most people aim for 70 to 80 percent, some people on here claim to get about 90 sometimes. I would do the back of the envelope calculations for you, but you seem to be using some weird system of measurement that I am not accustomed to... perhaps one of the members who lives in europe and has some familiarity with meters and liters and such can do the calculations for you or direct you to a place where you can do them.

I read through the batch sparging threads. Thanks. What I learn is that everyone does it differently. I went on a brewery tour and took notes and was concerned my sparging was different to that seen at the brewery (the grain bed, the gentle sprinkling). My tank is so big it all gets disturb in the wash. As some people stir up the sparge water and the grain anyway its clear that there are many ways to sparge. I have had efficiencies from 65% last week to 85% this week.

thanks for comments