Backyard Aquaponics
A place to discuss aquaponics

I am about to set up my living room fancy goldfish aquaponics aquarium. So I need to buy a pump. The standard water turnover recommendation for goldfish and koi is 10 times the volume of the tank an hour. So if I have a 55 gallon tank, I need a pump that is rated at 550 gallons per hour. I have a 200 gallon tank so initially I thought I needed a pump rated at 2000 gph. Then I thought it through just a bit more.

Fancy goldfish are notorious for being terrible swimmers. I think that is what makes the so appealing sometimes. They way the bumble through the water is just so darn cute. I could watch them for hours on end. So I would think turning over the water 10 times in an hour would make a lot of current in the aquarium too much of a struggle for them stressing them out. Furthermore, I would think water pumped into the grow bed would do better if it is done slowly before it is dumped back into the tank from the bell siphon. I am thinking turning over 200 gallons 10 times in the hour would not give the bacteria and plant time to get what is needed thus cleaning the water column for the goldfish.

So I think I might need a pump rated a bit less than 2000 gph. Say half that? 1000 gph? I essentially would be turning over the water in theory every two hours. Could I even get away with lessor rated pump, say 500 gph? I think the less current without sacrificing good water quality in the tank the better.

Does anyone have any advice with respects to this? I would really like to know your thoughts on the issue.

Cheers,
Keightley

10X per hour sounds like a ridiculously high turnover rate. We have half a dozen goldfish in a bath that isn't turned over at all, and they are doing fine. Even in my large AP system (currently ~430 rainbow trout) I only turn the water over a max of 6 times per day, and less when it is cloudy.

Of course if you have the goldfish packed in like sardines, you will need a higher water turnover rate.

Thank you, Gunagulla, for your thoughts. Does anyone else have any? How many times should I turn my water? At what rating should I get my pump? The highest the water will need to be pumped vertically is 4 feet, horizontally 8 feet.

With the proviso that I don't know how many fish you plan to put in tank, I really don't think you need a pump that will do any more than 200gph at 4' head. Just make sure you use a decent diameter pipe so that you aren't adding too much frictional losses, which will reduce the flow.

Running a pump to flow 2000gph @ 4' head is going to cost a fair bit in electricity, plus the fish will probably struggle to swim against the current... and there's nothing worse than a tank full of tired fish

>> Thank you, Gunagulla, for your thoughts. Does anyone else have any? How many times should I turn my water? At what rating should I get my pump? The highest the water will need to be pumped vertically is 4 feet, horizontally 8 feet.

10x is really too much. The recommended default is 1 FT volume per hour which is most often applicable to timer systems.
Constant pumping systems (using siphons or constant flood) might get 2-4x per hour.

You don't say what method you are going to use with 2 tanks and where the pump will be located.
But you do mention siphon so presuming pump in FT and siphon feed.

But for a 50-60Gal tank something 200-300 GPH would be fine.
and 200Gal anywhere 500-900 GPH would be fine. (2000-3000 LPH)
Just check the head-flow chart for whatever you buy and be careful with extra-cheap pumps.

One mistake often made is people buying pumps that are way too much for system because it costs just a little more.

If you have a little capacity you can put a 'T' in so some water returns for aeration
(mostly applies when pump in FT)


A gentler option for the fish might be to go with a sump tank and pump from that with just an overflow in the FT.
But for glass aquariums that can get a bit complex if you don't want to cut holes.
and is a bit overboard for a small system.
You can still have a within aquarium air bubbler for aeration.

also if you want gentle then maybe dont use siphons - they are optional.
you could easily do timer F&D with a standpipe and slow leak or a constant flood (or a hybrid of the two)
you wont then get the water rush (as above a sump would also avoid this'if you stay with siphons).

as you have two tanks you might be able to make that work with 200Gal as FT and 55Gal as sump with odd critter in it.