Winter is comming and greens dont realy grow that nice.I bougth a growlight its not to bad but is not good to.I lined the fishpool with hapostyrol and have heaters,build a minigreehouse over the Growbed.
Any more advice? I also can not but the system inside.
What type of fish? How cold does your climate get?
I can grow veggies all winter in my climate (heck there are some things that only grow well over winter.)
If you are growing a locally adapted fish (and it has already grown large enough to survive the period of not eating) then I wouldn't worry too much about letting the system slow down for the cold period. You just have to keep it warm enough that the water doesn't freeze and reduce feeding or quit feeding till the weather starts to warm back up.
If you are growing some tropical or sub tropical fish, you might need to heat the water more to keep them alive.