Backyard Aquaponics
A place to discuss aquaponics

I am new to aquaponics, and I am designing a system for an aquarium, but my first thought is that I want to minimize the use of my pump.

Do most people have a pump providing areation (air to the fish) and a separate pump for the plants?

I was hoping if I used one pump that I could hydrate the plants and that would provide enough air to the fish from the run off from the plants, but now I am not so sure.

I guess the other solution is to submerge the roots, then you don't have to water the plants, correct?

Thanks

It varies. Most people are only pumping water and the water falling back into the container provides all the aeration. Others have a separate air pump but usually because their fish stocking levels are high enough that this is needed.

In Aquaponics you're watering the plants with the fish water. In aggregate systems (where plants are in rocks or some similar medium) the water level is typically over the plant roots for most of the container depth and the moisture comes within 1 inch of the surface. There is plenty of dissolved oxygen in the water for the plants, fish and bacteria.

How many fish you have and how you run your pump will determine if you need additional aeration (above and beyond just pumping the water). Most people don't need the extra aeration for their system.

If you don't want to run your pump very often then you probably should look at Timed Flood and Drain. The water is pumped for a set duration and when this ends the pump stops and the water drains back into the fish tank (through a standpipe with a small weep hole). You might need an air pump for the fish if you plan on long periods without pumping water.

Cheers

welcome to the forum, since the forum search function has not been working i will not berate you now,

for aeration with water pump google "venturi effect"

for moving water with air pump google "air lift pump"

air lift pumps only work in certain situations where you are not lifting the water very far, but they can be amazingly efficient.

have a great day!

Looks like the venturi effect will increase water pressure, like putting your finger on a hose to spray it. Does this somehow effect aeration as well?

yes, maybe you should keep reading.

You don't need a venturi or an airlift, just pump the water up into your growbed and let it fall back down into your fish tank. Very simple, works well, not a lot of things to build or take care of. Put a standpipe in the growbed with a media guard around it to keep your media from plugging the standpipe or getting into your fish tank.

I discovered something this afternoon while checking my system after a heavy rain. The siphon actually sucks a significant amount of air into the water without the use of a venturi. Even when the drain is fully submerged in the fish tank bubbles continuously flow from the pipe while the grow bed is siphoning.

It depends on your temperatures. On hot summer days in texas this is not sufficient.

I think this is probably an indoor system based on it being an aquarium but it never hurts to have extra aeration. A spraybar would be another option.

Doghouseman,

Just to explain why we are having this discussion - at high water temps the water can hold less oxygen. Normally you won't have the high temps but you may need additional aeration of some sort during these periods. It's also possible to have oxygen saturation without any extra aeration other than pumping the water.

Ah.. thanks for the additional information. Yes, you are correct this is an indoor system, so it will be at more or less a constant room temp.