Backyard Aquaponics
A place to discuss aquaponics

Probably more like 40 - 60 litres.

Anyone taking book on this???

Nah way more Tony.... think Kuda is close to the mark....

My guess 235ltr

how deep is it and how big in diameter approximate? easy to work out the volume when you know the size

about 1mx1m by apparently 220mm according to an earlier post. So I calc 220L, then subtract some cos it's not square, round for convenience and I get 200.

But it may be just over 1m wide, in which case Rope's on the money

I took a guess at around 300mm deep ....

Gotcha Rupe!


Probably the first time I read a post more thoroughly than you did hehe

awww shucks

so I just went out and bought myself a pH test kit from "tetretest" . my nitrates are at the "between 12.5 & 20" on both my systems , but the pH on the smaller system ( pics at the start of this thread ) is at 9 , and the mint is going berzerk .....

the pH on my 200L / 2 GB system with 4 koi is at 7.5 , maybe towards 8

I read somewhere that pH needs to be above 7 to promote nitrification and it looks like the plants in that system aint doing much ( apart from a couple seeds that have sprouted , I think I recall putting blacktail melon seeds in there

So Im about to start raising my pH towards 9 , anyone want to stop me before I do that , or is 9 ok ?

Most definitely not. Don't even think about it. 7.5 was ok. The ph scale is logarithmic.

I would be concerned with a pH of 9.
Most fish will hate it.
African Cichlids often like 8 or 8.5 but I've not heard of anything higher than that. (Tilapia are cichlids I believe, but not African)

at 7.5 your pH is ideal.
if your plants aren't growing, but the mint is, there are 2 things.

I think mint is a high nitrogen feeder, and loves water, so it will go ape.

also the plants may be in shock, like my capsicums and chillis. My system has been planted for 3 weeks now see pics here
and some plants are starting to take off, others are still lagging.

more time, and then more fish is probably the way to go.
your nitrates could be higher than 20, but as you're planning on keeping your fish to a ripe old age, perhaps not more than 40.

P for patience I have heard more than once myself on this forum. I know it's hard, but it is necessary

Sh*t that was close hope he reads it.

Sleepe, fear not, he asked the question. A sane man would wait for a reply. We only made him wait half an hour...

If he didn't I hope they were not expensive koi.

:-) she'll be apples Sleepe, the others he already has at 8 are managing, long term harm may come of it, but not too much short term, unless he shocks them to death..