Working with an Aquaponics system in the Dominican Republic and we are having trouble with aphid and snails. Any ideas for organic pest management that will not harm the fish in the system?
Did you tried the ladybird predators (Coleoptera: Coccinellidae) to control aphid pests ?? I am not much sure whether the ladybird beetles would successfully control the multiplication of aphid pests in aquaponics......... but you may experimentally try them !!
I recommended biological control. Some predatory beetles and lizards feed on them, but birds and rats are the most effective.
GROUND BEETLES. Energetic hunters of slugs and other creatures. Breed more slowly than slugs & can't keep up with sudden slug increases. They require Summer nesting sites: stones or logs etc. Many species are active for only a few weeks in Spring & Summer before entering a resting period before laying eggs in Autumn. Require cover while hunting: under plants, debris, mulches, etc. Most species prefer moist shady conditions & feed mainly at night. A few are active in the day & prefer more open ground. Require overwinter sites: under logs, tree bark, in the soil or in a patch of rough grass. Most tend to move to woodland or hedgerows in the Winter. In Spring & Summer, ground beetles eat many eggs & young slugs. To encourage beetles, it is possible to construct the following "Pitfall plot":