Backyard Aquaponics
A place to discuss aquaponics

G'Day,

I have been looking for an underground water tank of about 2500 to 3000 liters capacity since a long time. Unfortunately the design I'm looking for seems to be non-existing in Australia
All underground rainwater tanks on the market are doughnut shaped and have no manholes thus unsuitable for aquaponics.
I am looking for a plastic tank (Foodgrade for obvious reasons), with manhole access for easy cleaning.
The only tank that comes close to my requirements is a septic tank made by Reln but it can't be guaranteed that these won't leach any chemicals in the water as they are made from recycled plastics.

http://www.reln.com.au/Products/Septic_Tank_3200L.aspx

Is there anybody out there who can recommend a tank that meets my requirements?

I don't want to use concrete tanks as these will effect the pH-control of the water.

Cheers,

Luc

I really want to see a members thread on your system if it needs a 3000L sump. Seriously!

Look up aquaculture tank on google and in your area, there are plenty of rainwater tank places that do them, I think it's what you're looking for.

Random google:
http://www.enter-shop.com.au/catalogue/c38/c160/p861

Concrete tanks can be used, it just requires sealing the concrete with a pond paint or something similar.

If you find a local maker of rotomoulded tanks you should be able to request it to be made from the same material they make drinking water tanks from. Though the ones you linked to come in two parts, they are probably imported premade.


Or - http://www.rapidplastics.com.au/Poly-Wa ... ter-Tanks/

Have a look at my thread- my ST and FT are buried, although not covered in dirt. I wouldn't recommend it in Antarctica though, it might freeze solid You dont have to bury it entirely (how deep were you intending to bury it?) just mostly bury it and put an insulated lid over the top, which also makes for easier access.
Regular polyethylene rain water tanks are fine, mine are in heavy clay, so there is no tendency for the sidewalls to crush the tanks. I filled the gap between tank and clay with sand. If in soil that is prone to collapse, fill the tank with water before backfilling around the tank.

Colum, 3000l isn't all that huge! Mine is 2500l, 2000l of which I am using, which is just enough for 9 * 500l GBs. My next system will have a ST much larger than that.

I also am looking at a 3000 litre ST for 10 300mm (h) ibc GB's. My thoughts are 3 x IBC's connected somehow?

My idea is to bury the 3 IBC's with 200mm protruding, cut the cages so that the 3 IBC's are together connected by 2 x 90mm screw fitting, outside cages wrapped in geotextile. And backfilled with sand to prevent stagnant ground water collection for mozzies to breed in.

Just curious (and I am glad you already have a system thread, I like big systems, read through it a few times), how often are you topping up with a sump that size?

With the sump EB posted, I think it's what Lrat wanted, I'm a bit sickly at the moment, so didn't read properly. But how do you clean it out when solids build up in the sump, or a dead fish makes its way into there? At the moment I have a tank broom that I woosh it all around with, and can see any dead fish that snuck through the SLO. I'm just having trouble imagining it with the oblong underground one.

At this time of year, every 1-2 weeks, depending on how much sun and wind there has been and how much time the ST has been uncovered to gain heat.

Yea, those UG tanks that look like submarines would be a big hassle to clean out!

Ok, so not underground as such, but how deep is the dirt you are going to throw on top of it? surely not much/anything at all.

You will never find a rain water tank with a "manhole", not below 100kl i dont think anyway.

not quite the size you wanted either, but maybe its another direction to look in:

http://www.asctanks.com.au/product-cate ... eck-tanks/