Backyard Aquaponics
A place to discuss aquaponics

Hi guys. Trout season went exceptionally well now I have 50x40mm silver perch in the 1000L tank with 1000L growbeds full of healthy plants. A few weeks after trout were harvested the system has used up all its nitrates. I'm looking to use Charlie carp until the fish eat enough to support the plants nitrate needs. Anyone know how much CC to add to the system daily/weekly to keep it running? Ill be keeping a close eye on levels with test kit but a rule if thumb would help as starting point. Thanks in advance!

I'd use Seasol I'm preference to CC. Seasol doesn't add any appreciable amount of ammonia, whereas CC does. Start with adding 20-50mL of concentrate to 1000L per week, add more frequently if the plants need more, but don't too much all at once.

I don't think its a good idea to add additional ammonia while you have fish in the system. Although they are small they will be supplying all the nutrients you need. Your system is using them all as they are produced and as such is functioning very well. You can add seasol if you are worried about the plants

Hi Greenhorn,

Your system will be fine and will carry on nicely with the fish load you have now. I personally wouldnt add any other source of amm. Of course the small SP wont be eating anywhere as much as your trout but they are still active and expelling amm through their gills and excretion.

Thanks for the advice guys. Ill stick with the seasol and leave out CC. I presume plants won't grow so fast now but as long as they don't die I'll be happy. Cheers

The plants will grow just as well with Seasol as CC. I have used both for many years (and if we ignore the ammonia content) both have the same affect on the growth of plants. If I had to choose one product over the other, I'd go with Seasol in AP because it smells less and although there may be some minor staining of the water, tea coloured water doesn't smell like rotting fish; sometimes CC can leave a slight film of oil on the surface of the water.

Lovely growbed photo Greenhorn!