For pest control I use Sundews, Nepenthes and other carnivorous plants. You have a varied collection of plants as well as pests, and it would be hard to suggest a solution that wouldn't harm your plants or animals.

You may have to remove the guppies while de-pesting if you decide to use anything other than natural pest control.

Sam

It sounds like you need some small dart frogs . . . (and the insanity begins) . . . .

I think your best bet is to remove the fish. Even topical pest control might drip into the water below, and while tea tree oil would be safe, I don't know about neem oil or rubbing alcohol. So put the fish in a holding tank one afternoon, go over all your orchids thoroughly with a Q-tip dabbed in your pest-killing solution of choice, and then rinse everything off and change the water in the tank. Soap would be a definite no-no, even if you do remove the fish, because any remaining residue would be toxic. No harsh chemicals, either. But then you could put the fish back in (aclimate them, since you've changed most of the water), and then get some carnivorous plants for future pest maintenance! =) They really do work very well. And a nep hanging out over the water would look very cool indeed. . .

Thanks so far for the answers.
One of the pests is snails, little small transluscent ones and others too. I think these can be bad for small roots. So maybe sluggo might be good to kill them. My terrariums use the fish water in the bottom as water and fertilizer through a pump and sprinkler system so any chemical I put into the water will get on the plants (and fish) so perhaps the iron compound would work. I guess I need to check the aquarium forum to see what can be used there. But does anyone know if sluggo is fish safe?

Also ideally I can find some compound that is completely fish safe while killing pests so I do not need to tke fish out.

Thanks.

I think that many fish and animal safe pesticides use BT, bacilus thorengiensis (sp?). I think its mostly used for caterpillars but it might work against certain stages of the insects you have...or at least some of them. Anyway I don't think it would hurt anything.

Since your water is circulating, I'd just add some mosquito pellets to the water and your spray system will distribute the BT. I've heard diatomaceous earth recommended for snails and slugs. Try to get some lady bugs to eat the aphids. Don't think you can beat the mealies and scale w/ out serious systemics. good luck!

Gee you have a lot of bugs. I have some friendly bugs in my new terrarium and plan to let them live there. My advice is to look up each type of pest on google and learn about it. Some might not be hurting your plants much, others have a specific weekness. I don't plan on using any chemicals, but I know that things can get out of hand. Anyone with a tiny pet tree frog would be very happy to have so many bugs. I read that insectivorous plants work great--see this posting this forum: sahoyaref Alberta z3a on Thu, Nov 18, 04 at 13:47

Scale and mealies can be killed by dabbing rubbing alcohol on them with a Q-tip. Same with aphids (it dries them up instantly). Diatomaceous earth might not work. I don't know if it's safe for fish (what if they try to eat it?). dfourer does raise an interesting point though. Why do you have so many bugs? It would seem that your plants are in very poor health. What is your humidity at? do you have any air circluation? Are you using only distilled, RO, or rainwater? (Guppies require hard water, whereas you should only use soft water for enclosed spaces like terrariums, so perhaps you should change your fish to something better, like a betta).