Lift Tubes

[Sgtomko]

Has anyone used or knows much about using lift tubes for water flow? I'm trying to design a 300ish gal tank using airstones at the bottom of pvc tubes to create flow. I have a vortex air blower, so I have all the air I need, just looking for feedback on this idea. I heard it was the most cost effective way to move water.

 

[dnjan]

Relatively low flow rates, and lots of salt creep.
Great for aeration, but not a good idea for primary flow in a single tank.

 

[Sgtomko]

I'm still in the designing stages of this, but the salt creep is an important thing to think about with this. A piece of acrylic at a slight angle just over the tank with water running down the underside, or dunked on a regular schedule would take care of that maybe?

I read Anthony Calfo's book on coral farming, he seemed to think it was a good way to move water. What do you mean when you say "not good... for primary flow in a single tank."? would it be good for more tanks?

 

[dnjan]

airlifts can lift a reasonable volume of water a relatively short distance, at a slow to moderate rate. So, if you are setting up a system of shallow channels, sloped downward for water to run through, an airlift would be a good choice to lift the water to the top end of the channel. Gravity (water flowing downhill in the sloped channel) would provide the velocity.

That is a good design for coral farming, but with a single, deeper tank like most of us use, it wouldn't work that well.

 

[DonW]

Give the folks at aquatic eco a call. They used to design air lift systems and may still if not they can steer you in the right direction.

Don

 

[Sgtomko]

a system of shallow channels, sloped downward for water to run through

Turbulant flow is best for corals right? Wouldnt the laminar flow in a design like this hinder coral growth?

Also, thanks Don, i'll check them out

 

[dnjan]

You can use partial baffles to get turbulent flow. But it is harder to achieve alternating flow.

 

[Sgtomko]

dnjan,
What do you think about a raceway set up in a normal shaped tank using baffles 6" or so apart. Using lift tubes to pump water in one side, and out the other. If the flow direction were randomly alternated you could get some nice wave like flow. Whats your oppinion?

 

[dnjan]

But your "tank" would just be a series of shallow raceways. Not great for viewing ...

 

[Sgtomko]

That is very true. I was thinking of doing this for coral farming; a for profit endeavor. Is this not the right place to talk about such topics?

 

[dnjan]

No - I misunderstood. I was thinking about a tank in the livingroom.
Raceways for coral propogation make sense. Shallow, so you aren't wasting light intensity. And salt creep isn't as much of a problem either (for propogation versus livingroom tank).
I think you will want to play around a bit in terms of raceway slope and baffle size/location for proper water flow. Also, consider making your raceways from something white to get better light reflection.

 

[Sgtomko]

Thanks for all the input. I'll let you know how it turns out.