How much air?

[seaweed88]

I am working on a system which could require up to 50 foam filters. How do I determine how big a pump I will need? I believe I need to work with :
Air Volume
Maximum Output
Maximum Pressure.
I am clueless about any of this and any help would be greatly appreciated..
Thanks
Mark

[EasterEggs]

I found the best place to ask air-type questions was on Discus breeder forums. They pointed me towards a Coralife SL-65 linear piston pump which I think would be pretty close to what you would need, and very affordable at less than $100. The depth of the tanks you're using is also very important. It takes much more force to push air down to the bottom of a 24" deep tank than a 16" deep tank.

[Scottt]

Just about all larger air pumps have a flow/pressure curve shown in a graph. If they don't you can imagine a curve by using the max flow (rated in CFM usually), and max pressure (usually in PSI).

The SL-65 is 2.3CFM max, 3.9psi max.
Some sites like aquaticeco.com have flow rates listed for airstones. The flow rate does depend on the psi a bit, but it's best not to worry about that. Just find the airstones you want, add up all the CFM for them, and then find a pump that does that for you.

I think the smallest airstones are 0.05CFM, 50 of them would be 2.5CFM. One sl-65 might work, but it would be right on the border. I think most people use the linear pumps these days like the sl-65 or more expensive brands. It depends on the size of what you are doing. I personally like the regenerative vortex air blowers. For flow in the 15+CFM range, they are much cheaper than the linear pumps, and very very reliable. I run my regenerative blower between 1 and 1.5 PSI (30-40inches of water).

Also, If running a system that requires air for the survival of the tank inhabitants, it is good to have a backup pump triggered by a pressure switch.

[seaweed88]

I am going to run a sump on both systems . I want to use the F1 media in the homemade filters in each tank for a back up. If the main circulation pump quits I will still have the air driven filters in each section. The max depth for the sections is 12 inches.
Thanks for the help!
mark

[Scottt]

Is that the Kaldness Media? If that is the one, it requires .5 CFM per cubic foot (I use ~.2cfm in one 5gal bucket of it).

[seaweed88]

Yes that is the media I am using in the filters. Do I need to build a PVC plenum to run the air to different parts of the room or will I be fine with just running air line and valves?

[Scottt]

If you're going to run 50 sponges, and Kaldnes in the sumps, I think a PVC manifold with air valves drilled in it would be the best option.
I tried all kinds of air-valves, and only the all-plastic ones last well with sat-water systems. Something like:
http://www.aquaticeco.com/subcategories ... stic-Valve
FAF sells them at a good price too I think.

You might be able to do it with airline and valves, but it will be much more finicky getting the air all even, and not nearly as pretty/functional. PVC is probably cheeper too, 3/4" would be fine for this kind of flow rate.

That is a pretty serious air demand, which is a good thing IMO. It helps keep everything alive, and gets the CO2 out of the water well. Place the air-pumps outside or in a separate room to get nice clean air. CO2 can really build up in a tightly sealed fish room.

I think you're going to need at least 2 of the sl-65 size pumps, or a larger more expensive linear pump. If it were me I'd do a small regenerative vortex blower. If you plan on growing a lot of fish having the extra air will be much appreciated in the future. They're just so reliable too.

I don't have experience with the nicer linear pumps, but the sl-65's need work after about 2 years of service. They are cheep, but you get what you pay for. For a couple years of use, their price is really good. But for a long-term project, I'd go for something nicer.

[seaweed88]

I am going to be using either the foam filters or the F1 filters. I will stick the pumps in the crawl space and see how that works. I have a chance to buy a pump which ran a system at one of the wal marts but I know nothing of these pumps.
Thanks for all the help!
mark

[Scottt]

Post some pics or specs of the pump that is available. I have some weird problem where I'm really interested in air pumps.

[seaweed88]

I should be around it this weekend and I will do just that...