Thread: Tweaking the Air Lift

Having had the system running for a while now I have been meaning to reduce the lift of the "air lift pump".
This was not as easy as you might think given the nature of my system, so I kept putting it off.
However, finally got round to it today as ideal to do in the Winter when fish aren't feeding and a few hours with everything shut down is neither here nor there.
So I was only able to reduce the lift by about 5cm, so you might think why bother? Well, with my Winter 25W air pump the flow rate has increased significantly - rough flow measuring suggests that in this case "significantly" is easily a 50% increase!
Just goes to show that with air lifts, lift height is everything!

Of course the Winter air pump is relatively weedy and I won't expect anything like the same % increase with the Summer one - but every little helps

Sounds like a good days work,so how far off the water level now UK?

Originally Posted by john1

Sounds like a good days work,so how far off the water level now UK?

It's not quite that simple with my system because the air lift is half way throught the filter bays - see diagram (back up air pump was actually replaced in the build with a conventional small pump as it can deal with greater head variations).

So, with the flow stopped the height difference is about 5cm.
However, with it running there is a drop on the supply side to give about 10cm of lift to top of outlet water level.
If I lower the outlet any further it would be counter productive - like I said, my installation is unusual!

Oh, and I have tweaked it further to have 15 baskets and almost full bypass of moving bed as needed.

I have seen your system on you tube when I was doing my own air lift and very impressive.
Must say I like the standpipes, old school but work great