Backyard Aquaponics
A place to discuss aquaponics

I have read that in soil based gardens, healthy plants don't have pests. This makes sense. I can't prove it in my garden of course; if pests don't bother something, they might have just not shown up that year.

Would this be the case in aquaponics systems? Or are they not natural enough? I know lots of members have had problems with bugs.

Does anybody have systems which never have problems? Does adding kelp or sea salt to the water seem to help pest problems?

This theory would seem easier to experiment with in AP. (Nutrients can be tested in the water.)

I think more than just the health of the plant is involved. I believe that the macro and microbial fauna play a big role in how well a plant does. Much of the resistance could reside in places other than the plant, like nematodes, fungi, predator mites, and the list goes on.

I've always thought plant signals were interesting - http://www.livescience.com/22241-sensor-could-detect-plant-distress-signals.html

AP is pretty much like soil in many ways including this.

All good in theory, but it is numbers game with pests like aphids and caterpillars. Aphids do prefer stressed plants but when they explode in numbers in spring everything palatable is targeted. Predators always take time to catch up as they need their food source before they have a signal to breed with confidence. Healthy plants are definitely more resilient to fungal infections. And of course healthy plants grow quicker shading out out soil and suppressing further weed germination.

Very true Santalum. When something gets out of whack, pretty much any system can collapse. How bad the imbalance is has a lot to do with the speed of recovery, if there is a recovery, or if you just have to rip the plants out and start over.