More trouble with barrelponics

I lost a couple of tilopia the other day. and no, they didn't escape from the barrel. I threw the other 2 in the other pond.  I will have to ask my good friend Sam at Queen City Hydroponics for any suggestions.  The plants may not have large enough roots to clean the ammonia out of the water.  The bacteria in the system may not have had time to develop into nitrates for the plants.  The leaves on the tomato plant are not doing well.  I will take these pictures to Sam and see if he can tell me.  Right now there are no fish in the system, however; the siphon is working great. That is good news, because all I have to do now is get the fish to plant balance right. Sam gave me some iron cloride to put in the water, because the plants need iron and the fish and plastic barrel do not provide any.