Backyard Aquaponics
A place to discuss aquaponics

Hi fellow Aquaponicists.

I have installed a venturi presently running off my 3900 LPH pump. From pump which is in the sump tank, One line goes to growbed and the other to the venturi and another returns to the fish tank. So there is plenty of movement of water, I can see fish and all is working (If it ain't broken don't fix it comes to mind)

However, having said that I have a huge kick ass exterior pump ( a Toshi ASP) that pumps 80 Ltrs per minute.
I connected the venturi to that and the movement of water is like at a surf beach. I have a retarding tap, but I think I read somewhere that that type of pump can't, shouldn't be tempered else it will cause damage? Maybe I am wrong there?

Secondly when I connect to the external pump all the waste matter on the bottom, doesn't settle, so it is being moved around the tank, I can't see the fish, they didn't feed in this scenario either and then their is the extra power costs. The latter may not be much, I will have too wait and see

So my question is
In a 1000 litre tank is there such a thing as too much water flow?

Yep!

Water turbidity can probably be sorted with a swirl or radial flow filter somwhere in the system, or even by just setting your grow beds up so the fines can settle in the bottom.

But I doubt fish like being on a treadmill that's on the "running from the cops" setting, 24/7.

When I used to live in the Pilbara, where there are big tidal movements, and fished the tidal creeks, or when I've fished rivers in the North Kimberleys, many of the best fish I've caught have been sitting in calm waters out of the main flow of water. Tarara Bar on the Ord river is prime example, massive water flow concentrated through narrow channels in the rock, and the fish can actually be seen sitting in the eddies catching a breather.

I don't know what sort of pump that is, but restricting any pump's output with a tap is exactly the same as pumping to a higher head, as far as the pump is concerned- there is a certain amount of resistance to flow and the pump sure doesn't know what is causing it!