Backyard Aquaponics
A place to discuss aquaponics

Hi i am in the process of putting together my first aquaponic system and i am thinking of using a 4500L rain water tank as the fish tank.i am planning to put the tank in the ground with the top sticking out of the ground about a metre. reason for doing this is to keep tank temp at a more stable temp throughout the year as we live in the wa goldfields and the temperature can be anywhere from -2 to above 40 degrees. i was planning on keeping the manhole on the top of the tank open, will this be sufficient light for the fish to survive and thrive??

How are you going to harvest? I've run fish in a tank in my shed with very little light coming through a curtained window throughout the day - with no issues other than them being somewhat frightenned of the light and you needing to have those low light conditions for them to feed. I would not personally recommend what you are suggesting though.

It will also depend a bit on the type of fish. Most fish are really happy with low light conditions though but as noted, how do you harvest? I would make sure enough light gets in the tank so the fish can tell night from day but that is probably all that is strictly necessary unless you are trying to breed fish that require a long photo period for breeding.
I have noted that when you have a fish tank really covered up, the fish tend to get really freaked out when you do open it up to have a look or harvest, this added stress is not necessarily a good thing and having a tank that is hard to access for harvest or maintenance is also not so good.

on my 600 gallon (2270 L) FT, I have 2/3's of it covered with a frame with blockout plastic (black) and one third with GH plastic so some light gets thru.... so the fish can tell day and night differences...

I have noticed that the side under the black plastic has no sign of alge at all... the side with the GH plastic (milky white) has some alge along the high water line... but very little

And looking at your fish is one of the best parts of aquaponics.

Thanks for the info, now that you mention it i havn't really thought about how i am going to harvest the fish.possibly could use a net long enough to reach the bottom, also i could cut out sections of the top of the tank and replace them with clear plastic (perspects) to let more light in. hopefully i will have some photos of my system progress to post soon.

Has anyone else done this? Burried a Rain Water tank that deep?

Thats exactly what I am proposing to do, I have a 5000L Rain Water Tank that is about 2m high, I want to bury it at least 3/4 of its height down. I will be cutting large permanent openings in the top, so it shouldnt really be that hard to harvest? No different than not burying it.

I want to bury it so I can have gravity syphons from the grow beds back to the tank, this does away with the sump and extra pump.

Made a mistake with the above post, Tank will be 2700L. Roughly 1400W x 1800H

Fish need hardly any light at all. I saw a system over near Melbourne where they had the fish in a shed that was totally sealed. The large shed had one small flouro light at the side with a double layer of shadecloth over it, so the shed went from pitch black, to fairly dark when the light was on..

Indeed, my fingerling stocks are held in a covered tank in the garage...

And the tanks in the Holmes-A-Court project will be in covered, inside a shed, with a small shaded window and a single "bunker" light...

Hi Dave

I completely buried a 1000 litre IBC that was 1metre by 1.2 metres (actually my brother dug the hole and I supervised

If you are burying a tank (or sump) I think insulation is worthwhile. Yes burying a tank will stabilise temperatures overall, however when the ground gets cold in the winter it will chill the water to a lower temperature than if the tank was above ground.

I have two systems, one where the sump is buried and insulated, and one where the tank is not insulated. The water in the non-insulated system is on average 7 degrees cooler than the insulated one all year round. Good for keeping trout over summer but not so good for Silvers etc come winter time

Fish Fodder,

Burying the tank for me has nothing to do with insulation or having to regulate temps. I live in Darwin, It varys from Hot to Hotter then back to hot. All under around 35C, which is cooler than when I used to live in the Pilbara where it went from Hotter to Stupid Hot then back to Hotter! Averaging around 45C

The whole question was Accessability and Simplicity. Doesnt matter now anyway, its what I have and it's what Im going to create a system from.

cheers
Dave

how the heck did you swing that one!!!

i had to dig my own hole, took me 2.5 days and a lots of blisters, but then i did do i the hard way ......
with an axe cause i dont have a crowbar


for all those diging tanks in my only advice is beware the soil types can change very quickly mine was 80% sand ( that bit took half a day ) and 20% hard gravel /clay (that took 2 days)
OHH and find somewhere for the dirt BEFORE you start diggin it just gets in the way otherwize

CHeers
pete

I saw that you live in Darwin after my post and it made me think. It would be interesting to know what the ground temps are in Darwin 1 metre down in winter and whether water in a buried tank that deep (or deeper) would get too cold for Barra for instance.

Probably not but I don't think Barra like temps getting much below 20 degrees.





My brother is a kind benevolent soul and besides I was recovering from back surgery so he took pity on me