Backyard Aquaponics
A place to discuss aquaponics

I am building a sump tank ,what size should It be in relation to a 250 or 1000 litre fish tank

Hiya mr jp, st's are more sized for the gb's than ft's, it should be able to hold the water volume of the gb's.

Hi Mr JP my sump is sized to the gb as skeggley has stated and mine hold more than the gb with about 100 liters spare this helps when you have evaperation and if you plan on having anything else in you sump keep in mind if you pump from your sump to your ft it will need to hold enough not to run the pump dry hope this helps.

Right now I'm running one equal to my fish tank size and twice the size of the grow beds. But that is because I'm going to add more grow bed space in the next few weeks.

Yeah as big as possible... If you size it to a minimum, you have to keep topping it up more regularly.

If your running constant flood then it doesn't have to be as big.
Timed flood and drain - well the sump has to hold the same as the growbeds - growbeds have roughly 1/3 of the water with media in them.
Also depends on your pipework returning the water to the sump - if you pump is big and your pipe work not - then the sump will run dry.

I have 2 systems both have 1000litre fish tank.
I have 2x half IBC's for sumps on both systems - works fine with around 1500 litres of media for growbeds and would be fine with more growbeds, a bigger pump, and constant flood.

Even when running constant flood your sump should be large enough to hold all the water in your growbeds plus some. This is because in the event of a power/pump failure your beds should completely drain via a couple of small holes in the bottom of the standpipes. This is because you don't want to have stagnant water sitting in your growbeds.

I like a sump to be the volume of the media in the beds.. 500L of media, 500L sump. Leaves some room to play and means you're not topping the system up every 2-3 days when the weathers warm. You'll be amazed at how much a system can consume when it's full of booming plants in the middle of summer.

AHhh - will do this asap.



Yeah good point and its more stable to fluctuations as there is more water.

This is what I have, 500L grow bed 500L sumps(1500l GB and 1500L Sump in total), I have actually considered adding an extra 1000L of sump a few times just to give myself more room for movement of water, also tossing up adding an extra GB/Sump as I have the room.

Winter is the big thing for me, get heavy rain and it floods my sumps... guess that's everyone's problem though. I have my sumps auto fill via a cistern valve that is connected to my Bore so it gets topped up daily.

I reckon that an in-ground sump will help stabilise your FT temperatures, and the greater its volume the greater the effect. In my part of the world this would translate to keeping Rainbow Trout longer at the end of the season as the daily air temps increase and keeping Barramundi longer at the end of their season as the daily air temps decrease.

Possibly of even more importance to the typical APer is the stabilisation of daily temps that a large volume sump would provide. Swings of several degrees in temperature between night and day would not usually be encountered by the species of fish that find themselves in an our AP systems, I am guessing, since in 'nature' they would exist in larger and more thermally stable bodies of water.

A difference of one or two degrees could mean the difference between a close call and a mass fish kill, so going larger with your sump could be well and truly worth your while, Mr Johnny Pink.

Reason I mentioned sump tanks ,when measuring the stands the sump tank didn't fit ,so I imaged digging out the greenhouse floor to accommodate sump tank ,I had over looked the fact the sump tank fitted In sideways ,well I was relieved ,my measurements where correct. I am using the bottom of I B C ,that will give me about 600 litres hopefully that will suffice .I plan to insulate ,using plastic polystyrene ,put In roofing Insulation ,fold over sheet seal ,cover with plywood frame ,then paint. Weather not very good cold raining frost tonight

I forgot to thank members for advice THANK YOU

I forgot to thank members for advice THANK YOU

Hold on Jayendra and anyone else planning on putting holes in the standpipes for CF!

Hey arbe, get this out of your head . There are not supposed to be any holes in the bottom of the standpipe for Constant Flood. If you look back through the threads you will see that having a hole on one end of the standpipe lets you flip back and forth between CF and timed Flood and Drain or a siphon system. The hole is down for Timed Flood and Drain or if you want to use siphons but not for CF. The plants will be fine for long enough to get the power going again (at least a day). You don't need to size the sump for the water from the growbeds, just the water that comes from the pipes. Even that won't be much if you plan them to come upward, then into the sump. This is what makes it easier to expand than the other systems - every time you add a bed you only add the water for the growbed and the additional piping but you don't have to grow the sump to handle the extra water from the growbed or most of the piping.

Cheers