Backyard Aquaponics
A place to discuss aquaponics

Hi all and welcome to my system. I'm based in the UK and its a relatively small setup in an 6x12 wooden greenhouse. The tank can hold up to 1000 litres buts its currently about 2/3 full. I started with 10 mirror carp but I've lost one fish and I have another that's not putting on weight. The others seems to be fit and healthy and the water tests all check out fine. As I stated I'm a noobie and I've built the system with information I've got online. I had some initial problems with ammonia and nitrite levels and plants losing colour from leaves and then gradually dying but all the plants are coming on strong now. I have a high level plant bed with pump and syphon, this is working great, it fills and drains about once an hour. I also have a low level trough with a pump from main tank and a sump pump to empty back into the high level growbed. The pumps are working ok, I sometimes have an issue were the lower level tank doesn't fill enough to kick the sump pump into action but this rights itself on the next cycle. I do have a strange issue with the lower level trough. I'm using expanded clay pebbles and I've found these do float a little. The trough fills and drains and because the trough is narrow at the bottom and wider at top its seems to push the pebbles gradually into the centre and pull these down in a circular motion. I've tried some smaller plants in here and if you start them at the edge they will gradually move to the middle and then be sucked under. I currently have a couple of cucumber plants in and these are actually a fair bit taller, its just they have been sucked down. I was wondering if anybody had come across this before and had any advice to solve the problem. I tried putting in some driveway grid but this just pushed up out of the bed and killed a few saplings. I also would like a little info about stocking. I started this system with 10 carp but I've read the ratio of 1inch of fish per gallon of water or 1lb of fish (fully grown) per 8-10 gallons of water. If I have 150g of water in the tank, this would work out 150 1 inch carb, how do I calculate the magic number assuming that carp can get pretty big. I will be using some of the fish for meals when things get big enough. Thanks for reading.

Welcome to the forum Rob .

The problems you're having with your expanded clay media - basically you have the water depth set too deep so the expanded clay is not settled on the bottom, it just seems like it is. Some people have had plants completely disappear because of this. FWIW, most of the clay will eventually stop floating.

Hi, thanks for the reply. A lot of the pebbles are floating a bit at the moment in the trough. I've gently lifted the plants out a little so fingers crossed I haven't shocked the roots too much.