I wish I could say how much pesticide would remain persistent in the gravel or the filter media, but replacing water ought remove most of it and then there wouldn't be a need to replace the filter media, thus eliminating the need to re-cycle the tank. If you go that route, the simple one, I would test out some feeder comets or guppies to see what happens.

Fill it with water and put in a cheap fish. It it lives and it probably will your good to go.

I would think after six months of sitting empty the tank is going to have to be re-cycled anyway unless you have been feeding it. I think just to be on the safe side I would take everything apart,clean it and start all over. I would also re-think your selection of fish. Ryukins do get big enough to eat White Clouds. I used to have a large one that lived with a group of large Angels and he loved the feeder guppies the Angels were fed on occassion. Blue Lobsters also like to snack on small fish and the fins on a realativly slow moving Goldfish might be a bit too tempting.

Lisa

We really can't be sure about the persistance of these chemicals in the home or the aquarium. I would filter with activated carbon, and do a lot of water changes...the Republican solution to pollution...dilution!!!

Anyway, I would re think your fish selection too. Plecos and similar algae eaters are warm-temperature fish which will persistantly bother the slow-moving ryukins, the slime coat on those fish is too tempting for the plecos. White clouds and ryukins enjoy cooler water, but the ryukins might eat them if they could catch them, but I would't be to oconcerned. Inverts like lobsters would probably not be a good idea, unless you want them to eat the goldfish.I would stick to one theme, since the fish and plants naturally go together..for example SE Asian streambed with barbs and minnows, Amazon swamp with angels and tetras, or if you want goldfish consider planting reed-like plants like Valisneria and elodea with just the ryukins...mkes much more of a focal point and everything "fits" Just my personal opinion though. Have fun.

Thanks for the advice. I really don't want to kill any fish on purpose, so I am going to run several water changes through everything. Then maybe I'll try some plants and 1 fish-just to see how it goes before adding more.

I appreciate the advice on fish selection. White clouds are listed as companion fish as are plecos. I didn't realize they might be seen as "snack food" for the goldies.

I didn't know that about the blue lobster; I didn't see anything about temperment when I was looking them up.

I am probably going to stick to the ryukins and plants. Thanks for the plant advice. That's been the other factor interferring with my start-up.

I'll post a picture once I get it set up. My new camera has an aquarium setting!

Jan

You will need to do the fishless cycling all over again unless you have been ammonia to the tank all along. I am reading through the lines and guessing that you have not done this since your tank is half empty. Do not buy fish and put them in unless you plan to do a fishie cycle and then you will need to pick something very hardy such as danios.

Do I have to throw out the gravel?

I believe so. I have had fish die from this before and they were very highly priced fish. I would change the rocks to be on the safe side.

How much contamination remains in your tank equipment will depend on what was in the flea bomb.

All pesticides degrade eventually. Some degrade quickly, others slowly. Some degrade to harmless substances like CO2 and water. Some degrade through a series of variously toxic substances.

It's been like forever since I've had to use a flea bomb or any flea sprays at all - I stick to very very short haired dogs, with pergo flooring; fleas don't like that combination. But my impression is that most flea treatments these days include, or are based on, insect growth regulating hormones. I would not expect these to have any effect on the fish. Crustaceans maybe, since they are in the same phylum as insects. But not fish. Another common ingredient is pyrethrum, which breaks down to CO2 and water in a few days. But there's a new chemical out that's used in the flea treatments you put on the dog - imidacloprid, or something like that, and I think I heard it's very toxic to fish. I know I heard it's very toxic to bees. But again, every pesticide degrades over time and exposure to UV and microbes.

Get a can of whatever was used for the flea bomb, and check the label. Find out what the active ingredients are, and look them up on the Pesticide Action Network website. You should be able to find information on hazards to fish and other aquatic life, as well as degradation time.

Keep in mind that bacteria see pesticides as just another food source. Some might contain harmful metals or other compounds like dioxins, but bacterial and UV degradation are pretty reliable otherwise. And plain ol' dishwashing soap with lots of rinsing is how chemical applicators clean out their spray equipment - minimum of 3 rinses, filling the tank half way for each one. That should do the gravel. Scrub the rocks, and rinse well. Replace the filter media.

Then do a feeder fish cycling.

Here is a link that might be useful: Pesticide Action Network

put a couple of feeder goldfish in it and see what happens. You might grow to like the goldfish since they have a nice personality and are pretty tough as well.