[eparreno]

On my 20gal long, I have a couple plants which are growing emmersed cause they are so tall. I also have a living wall that drains into the tank. However it seems that one of my plants was infected with aphids and as a result most of my plants that are out of water are infected by aphids now.

I can't use insecticide (at least not commercial) because the water drains to my tank and would kill the fish.

Does anyone know how I could combat the aphids? While still keeping the water non-toxic?

 

[bigbadjon]

If you just spray them off would they wash off into the tank? That way could drown them.

 

[cjp999]

Outdoors, natural predators would keep them in check (lady bugs, lacewing, parasitic wasp). If they get out of control all you really need to do is knock them down with a stream of water, and then the predators keep the numbers small. Inside you have no predators, so it's going to be much harder. I would still start by trying to spray them off as already suggested. You are going to need to inspect the plants daily for infestation, because there will be eggs left behind. You want to make sure you kill off the newly hatched aphids before they lay legs eggs themselves.

 

[eparreno]

At the very least, I'll be able to have a natural supply of live food (;

Thanks guys

 

[TheAnswerIs42]

This is one tricky dilemma. I have been thinking about this for a while now and what I would do in your shoes, and I think one would have to use multiple approaches to eradicate them.

Firstly, I would recommend aggressively trimming back the plants that are infected the worst with selective trimming on the plants with moderate infestation, combined with manual crushing and dropping them in the water for free live food The most infested plants will not be able to recover and keep looking healthy, so you might as well just cut them back, same goes for selective trimming on the moderately infested plants.

Secondly, I would recommend using lemon juice - that "Real Lemon" stuff from the store - and dilute it 50/50 in a spray bottle. Spray the bugs directly, don't use the mist setting, the less that gets on the plants the better as it might burn the leaves. 30 minutes after spraying, rinse the bugs off the plants with fresh water. Repeat every 3 days to interrupt the egg to adult life cycle. Once you see no visible signs of the bugs, continue for another 3 treatments. The lemon juice will irritate and burn the aphids and weaken them (maybe kill), and when you rinse off the plants more will drop off than if you rinse without spraying. The lemon will increase the acidity of the aquarium water, but only very slightly. This can be controlled with frequent water changes during the treatment cycle.

Best of luck