Backyard Aquaponics
A place to discuss aquaponics

I'd like to build a small aquaponics system, and I think I get most of the basic concepts, but I'm quite confused about pumps. I understand that you need a pump to get water out of the fishtank and into the grow beds, and I've read that it's supposed to be able to pump the volume of your fishtank every hour (right?). Could any of you give me the name/brand of a *solar* pump that would do the job for an 85 liter tank? Even if I can't get that exact model, that would be a really helpful place to start understanding what I need.

Also, is a separate pump also needed to aerate the water, or does the water trickling back from the grow beds take care of that?

Cheers!

Mangobingo,

the actual placement of the pump will depend on your setup. But anyhow you will need at least one pump in the system.

The 'general' recommendation is to have a pump rated to be capable of moving all your water in an hour. So you'd require a pump rated at 85L/h.
However you should take into considertion the height that the pump has to overcome. Most manufacturers rate their pumps at 0M. An unlikely requirement for you! Most pumps will have a graph on them that shows how the rating drops off at different heights (the head). So make sure you have a pump capable of pumping 85L/h at your required head.

And then, you should add a buffer to allow for losses due to pipes, joins, bends as well as consider possible expansion.

85L/h is actually pretty small. You should easily be able to find a solar pump for such a low capacity. I'd look for a pump for up to around 500L/h. The excess capacity can be used to ensure you have a good water flow. A pump with such capacity can also provide sufficient aeration via devices such as rain bars, fountains or venturi, so you won't need an air pump.

Are you going to look for a pump with battery capacity so that it will run in the night? If your FT is well stocked you will have to consider the nighttime/cloudy day requirements for the tank.

Sorry, I can't recommend any actual pumps for you, but depending on where you are you, should be able to source something online.

Best
Paedur

Yes a little more info about your planned system would better help us to help you.

85 liters for a fish tank. I hope you are only planning to have some gold fish in such a small tank, I don't think you will manage to grow out edible fish in something that small.

I don't know of any "solar pumps" I've seen some solar fountains but about all they do is splash some water and I don't know if they would be able to move the needed amount of water around the system and it definitely won't do you any good overnight or on cloudy days.

I think you will need to do some extra research into some pumps as well as into small solar power/battery set ups since I think it will be a bit more complicated that simply buying a "solar pump"
I know of some nice small energy efficient pumps that I am running in a few systems currently. The smaller models might be appropriate for your situation though you would still need the solar panel, battery, charge controller, and power inverter.

Good Luck

Thanks a lot, that's really helpful information! My tank is 85 gallons (=320 litres), so I'll definitely be looking for a larger-capacity pump than most of the small ones you find when you search the web. I'll post what I find (one day, if it works...) in case others find that useful.

Btw, what are the energy-efficient pumps that you use, TCLynx?

Quiet One Pond pumps

I'll have to find a link for you or perhaps upload the PDF with the specs.

I may be a bit biased since I can sell these but the only reason I asked for a distributorship was because I liked the specs of them.

Hang on I'll upload the PDF to my site so I can link it here.

Here is a link to the pdf for the quiet one pumps
http://www.aquaponiclynx.com/q1pondDS.pdf

Mangobingo-- You can get a low power (45 watt) pump at Home Depot. About $42 on the main land. Harbor Freight sells a solar kit (85 Watts) for about $240. Again on the main land. Through in a battery for night operation... I would suggest setting up the fish tank to gravity feed the grow beds so you can limit the amount of water being taken from the FT. Place the pump in a sump tank under the grow beds. The pump will easily lift 7 feet. I have this setup now. Haven't converted to solar yet but that is the plan. Check out youtube for a couple of videos I just did. Search for OrganicGringo...

TCL
Can you get these pump over here on OZ??

regards
Matt