Air lift

[matseski]

I am considering building a few air lifts to run matten filters on a breeding rack. I don't need much/any head pressure, so this seems like a good application for them. Does anyone have any experience designing these? In principle, all you need is a piece of pvc pipe, a coupling, and an air hose connection for each one. Swiss Tropical sells some German made ones for $12+. Since I need 20 or so, I figure I can build them for $1-2 each.

I plan to bend the pvc to avoid any connection seams to improve the flow, but after that, I am at a loss. I am sure some experimentation will be necessary, but I wanted to see if someone here has some advice or owns a commercially made one and could explain their construction. Naturally with a bunch of these, I need to be concerned with efficiency to avoid buying too many air pumps and I suspect that it will primarily be determined by the bubble size and method of injection. I have seen some DIY projects where they simply glue an airline hose to the bottom, others where they attach an air stone, others where they build a surrounding chamber with a bunch of small holes drilled in it. I cannot tell which design the German ones are, but I suspect similar to the chamber with holes based on the bottom piece.

Does it make a big difference? In general, for small diameter tubing (1/2-1") do I want faster moving large bubbles or slower moving small bubbles?

 

[deeda]

Before I switched to the Jetlifter from Swiss Tropicals, I just used 1" PVC pipe and elbow, drilling a small hole in the elbow to accept a rigid piece of airline tubing that stopped about 1/2" above the bottom of the vertical part of air lift pipe. No air stone.

You are correct that the new style S.T. Jetlifter have multiple tiny holes around the base of the vertical uplift pipe, the gray piece on the bottom is the air line connector and 'feeds' the air to the tiny holes.

There is an obvious different in the amount of flow between the DIY and Jetlifter so I eventually switched to only them. They use metric pipe so won't fit U.S. PVC.

Tank height will determine air pump size so if you will be running taller, multiple tanks or multiple air lifts per tank, consider getting a central air pump rather than individual smaller ones.

What size tanks and how many are you planning on running?

 

[matseski]

To start, I am planning a pair of 40Bs, 4 10s, and 6 5s so I will be going with a central air pump.

Could you estimate what size holes they are using? I cannot find a source for the jetlifter piece nor would I have easy access to metric PVC so I am going to try to make some. It should be very economical and I have the time. If you could take a picture of one of them showing the details of that piece, it would be greatly appreciated.

 

[deeda]

The holes are probably 1/16" in diameter, all my small drill bits are broken but a small paper clip fits through the hole. There are 36 holes total, 3 rows of 12 holes.

I don't have a pic of the piece and my camera is down, sorry.

We were going to try and DIY this piece but we don't have the tools to fashion it. Picture a PVC coupling, drilled to accept a fitting as the airline connector, this is the easy part. Now you need to remove some material from the inside of the coupling to allow the air supply to 'reach' the holes on the standpipe and still keep the air from escaping around the coupling. I have a very poor explaining skills so you might want to consider buying one Jetlifter to see how it is built.

Your shorter tanks won't require the large size Jetlifter (too tall) so maybe buy the small or medium model as a test sample.

 

[matseski]

Your explaining skills are just fine! I am planning to try simply drilling out the center of a coupling to thin the walls which should be very easy on a lathe.

I will probably end up buying one of the Jetlifter ones as a comparison to measure my designs against. There are a few obvious modifications that I think could improve the performance.

 

[pescado209]

any updates on this experiment ?