Central Air Supply.

[troyclark]

I need some advice on plumbing an air supply. What I have in mind is one attached to the ceiling of my fish room. I am planning on doing a complete loop since I heard this is more effecient and PVC is cheap. It will be a look about 12 feet by 12 feet square to fit my room. What size of PVC would you recommend? I will be supplying around 20 (ranging from 20's to 55's) tanks with sponge filters and supplimental aeration. Probably a total of 30 or so outlets. I do not use airstones on any of my sponge filters and only use air stones to provide addition aeration when medicating. I was wondering if I need to buy a linear pump or if two or three luft brand pumps which I already have would be enough. If I do need a linear pump, which is the best and most economical. I don't have alot of money to spare so need the best for my bucks. I would appreciate any feedback. Thanks

Troy

PS. why are discus so addictive ????

[Cosmo]

Troy,

I would say you definately need a linear pump going by what your'e stating your requirements are. My suggestion would be give John at Jehmco a call and run it by him to see what he suggests... good guy and very knowledgeable so he could help you pinpoint what size pump you'll need.. plus.. sells a large line of quiet linear piston pumps (I'm looking at picking one up soon).. phone number on the website jehmco.com

hth
Jim

[mutfish]

I use a Jemco LP H80 linear pump in a 8x10 room using only 3/4" pipe in a loop with 35 outlets and I'm sure I could run twice as many.
Although larger pipe is cheap, I used 3/4" because it "fit" better in my tight setup. I still don't think you have to go real big diameter........

[lauris]

i just installed two linear air pumps in my fish room. if you look at my past posts, you can find the thread on that. there was some real good info shared regarding size of pvc, loops, etc. with a linear pump, 3/4 inch pvc was fine, and 90 degree angles weren't much of a problem. loops are not really necessary due to the lack of back pressure, or something like that. you probably end up with a loop anyway just by going around to all the tanks. i saved a ton of money by buying the linear air pumps off ebay. like twenty bucks instead of two hundred. i actually hooked two smaller ones to the system in tandem and i couldn't be happier. probably fifty outlets and seeming power for more.

[SantaFeDiscus]

I have one pump that supplys air to 12 outlets. It could pump many more though. I used 1/2 in pvc. I think a smaller diameter is better as you don't lose as much pressure, but I don't think there would be much of a difference between 1/2 in and 3/4 in. One thing that you should keep in mind though is that whatever tanks you are supplying air to they should be similar in height. I didn't think about that and originally planed on having every tank being supplyed by the one pump, but once I set it all up the air came screaming out of the 20 gallon tanks and 30 gallon breeders but nothing came out of the 75 or 85 as the tanks were much taller and more water pressure to fight. I could have set up regulaters on every outlet and tighten up the 20s and 30s and opened up the valves to the 75s and 85s but this would require valves on every outlet and I decided to just use the one pump for all my breeders and 20s and 55s. My bigger tanks I use a seperate double outlet pump for each tank. Hope this all made sence.
Fred

[Moon]

One of the problems with piston type air pumps is the control of back pressure. If the back pressure is not controlled the pump will fail prematurely. One way of overcoming this is to have a reservoir of air. The pipe around the room can perform this function well as long as it is sized properly. It the pipe size is too big (larger reservoir) the pressure will drop, resulting in nut much air in deeper tanks.
I use a small blower. This provides lots of volume with limited pressure. Back pressure does not affect blowers. My pipe size is 1.5 in which feeds about 30 outlets, mainly sponge filters.
HTH
Joe

[Mr. Limpet]

Fred, one way to overcome the different tank heights is to use the pressure compensated drip irrigation fittings. they come in .5, 1 and 2 gallon per hour.
If you install one in each line to each outlet, it will balance the airflow in all outlets. It even keeps the air going in full tanks when you are doing large water changes in others. They are really cheap at the hardware store. I use the 2 gallon per hour, I think they are the green ones. Give it a try, it is a very inexpensive solution.

Joe, I will have to think about your statement that a large tube/resevior will reduce the pressure. It seems to me that once it is full, it will pressurize just the same as a small tube. But, there might be some strange effect going on. Soes anyone have a copy of Aquatic Engineering that might provide some insight?

Take care, Paul.

[SantaFeDiscus]

Paul-
Great solution to the tank height problem! I have used the exact little g/hr things on irrigation in gardens! I didn't even think to use them for air This is the benefit in sharing with others is that you learn so much at the same time
Fred