Backyard Aquaponics
A place to discuss aquaponics

I'm working on setting up my first system. I have decided to go with a system that utilizes used 55 gallon plastic drums. I plan on using one drum as the fish tank and one drum cut in half length wise to use for the grow beds. I want to use a 6 inch pvc pipe filled with pea gravel as a biofilter. I plan to use perlight as the grow medium. I will grow either tilapia or catfish in the tank depending on which one is going to be easiest to get and take care of, I have a feeling it will be catfish because of their temperature range and they are native to where I live.

Ok so now that you have a feeling for what kind of system I'm planning on setting up here is my question, How many gallons per hour should I plan on circulating?

Here is the problem I have run into; I want to be able to run my aquaponics system completely off of solar power. So I want to use the smallest amount of electricity possible.

I originally planned on using a water pump, but it would require atleast 5 feet of head. Every pump I have looked at has required about 80 watts to pump the water. 80 watts is to much, I would like to use around 15 watts, so now I'm looking at an airlift pump.

Any suggestions or comments on the system?

I'm using a 23 watt eheim pump on my two half barrels and I could even do with a little less.

Air lift pumps usually don't give very much head either.

Just a few tips, head is measured from the surface of the water not the bottom of the tank.

I have been running a barrel ponics system using a 20 watt pump. Harbor freight had some nice little pumps really cheap so I bought a couple extra even for backups or to run a hospital or quarantine tank.

In a 55 gallon barrel you are not going to grow very many fish out to eating size but it is a good system to start out with for practice.

Your solar powered pumping, are you going to have a battery bank so that you can pump at night too? Fish need the aeration over night even more.

Where are you located, your profile doesn't say. I have channel Catfish in my big system and am hoping to try some tilapia in a different tank of that system. I'm in Central FL so will need to provide some temp protection on the coldest nights to keep from hurting the Tilapia. If I want them to grow fast year round, I would need to provide some supplemental heating to keep water up at 70 through the cooler months.

PLEASE - dont use perlite !!!! It is a MAJOR PITA

It will eat your pumps for breakfast, no matter how you try to contain it, it will escape. It also does not support taller plants because they just float out.

I recomend having the fishtank barrel on its side, with a hole cut in it, ala barrelponics like the sdecond photo on this page:

http://backyardaquaponics.com/forum/viewtopic.php?f=18&t=3047&st=0&sk=t&sd=a&hilit=barrelponics&start=15

Also I find barrels cut in half the other way much easier to work with, no sagging or having to support the sides. Have a look at the system in my Sig, towards the last couple of pages.

Pump size, around the 20 watts size as per TCL is fine for your size of system. It should pump enough height. Airlift pump wont even think of doing it.

Agree otback ,, especially re airlift pumps ..... these things where never designed to moove more than a few inches ( ahhhh cm's) above surface level ,, they are more of a movement , circulator and aeration device.

I've forgotten the name of a it ..... maybe Perri -pump ,, but it's a nice air operated pump if you really want to go that way.

Airlift pumps are able to lift air to a head equal to the depth of the start point of the bubbles, less some losses.

there is a 'geyser' pump, that is able to lift water MUCH higher, but in spurts. This makes an airlift work more like a piston pump.

But I acgree, they're best for making currents

Kuda ,, you may want to quantify that statement . I suggest a 5 watt air pump running an air-lift sunk to the bottom of the Pacific ocean ( may perhaps not lift water 11 km in the air).

I could be wrong but I don't think so.

the ABSOLUTE MAXIMUM provided you can supply enough air.
it's a physical limitation of the principle of airlift pumps.

[sarcasm]Just because the coldest temperature possible is 0 Kelvin, doesn't mean every day is going to get that cold...[/sarcasm]



Would a 5W air pump be able to pum air 17km below the surface of the ocean?

Is it a submersible air pump?

energy was not a function of Kudas formula, so i dont see any reason why you couldn't airlift that high as long as you provided the power to drive the air pump that is going to supply > 166.67 MPa

yeah, wot he said... my explanations have always been below average...

Probably what your rabbit thought too

And now back to our original poster burtonridr,
Is your system a full barrelponics system with the flush tank or are you just using one barrel for fish tank and one barrel cut into two grow beds?
I ask because the flush tank allows one to have a very slow pumping rate yet still get an effective flood and drain cycle on the grow beds. With a very slow pumping rate directly into the two grow beds, it may be difficult to balance the inflow with the siphons to get them to work properly within half barrels.

The small tank on top of the flush tank allows for a little more growing space as well.

Do you have pictures? I'm having a hard time visualizing what your talking about doing.

Sorry for the confusion, if I go with an airlift it will not lift the water more than an inch or so.

Someone mentioned something about feet of head being measured from the top of the water, that is true, for some reason I was thinking that because it is submerged it would have further to pump. But gravity will still push the water inside the tubing up to the water level....



Yes that is exactly what I was thinking of doing.... give me a minute and I will attach a rendering of the current design, maybe that will help.

Keep in mind this design was for a submersible pump, not an airlift. If I go with an airlift I will have to get rid of the vertical grow beds and lower the horizontal grow beds to allow for a siphon back into the fish tank.