I didn't realize such large changes were beneficial - as a first time aquarist (?) I was worried that too much change would inhibit the growth of the good bacteria. That thinking is old school and a myth. No sucessful breeder follows it. Some pet stores however continue to tell their customers that and if they had even bothered to read the fish mags they sell they would see, 10 - 20% water changes is no longer recommended. We change 80%, cleaned the gravel and the filters at the same time and there has never been a rise in ammonia or nitrite levels. We used to worry about it in the beginning but after testing the water parameters after each change, we learned it didnt harm anything. Koi and goldfish, contary to popular belief, need alot of room. They are big messy fish. Your 40 will not be big enough very soon. You will find yourself either upgrading again to a 60, then a 100 and in time a 200 just to keep the koi in the tank or you will need to trade him back to the place you got him. They get big, to about 2 1/2 feet long and grow up to 4" a year. Another myth is the fish will not outgrow the tank. What happens there is the water pollution gets so bad that the fish gets stunted, sick and then dies. (think goldfish in a bowl). With proper nutrition and a clean healthy enviroment they will grow and grow fast and live 50 - 100 even 200 years. The record holder koi is 230. You will need to clean the gravel with every water change, get a siphon with a gravel filter. If you have sand in that tank, get rid of it and switch to a thin layer of gravel or gravel and an under gravel filter plate. Personally we got rid of the under gravel filters and went with a thin layer of gravel as that easier to clean. You need super filtration even on your 40. Do you have a hang on filter and a cansister filter? You need them. And as for your original question, is the water good for the compost heap? Your going to generate too much and it will make it too wet. Water the lawn or your plants with it, they will love you for it!

I'm into Aquaponics so I know that the nutrient rich (read nitrate rich since most bio-filters change ammonia into nitrite and nitrite into nitrate, once the nitrate gets too high, water changes are needed but nitrate is far less toxic to the fish than the other two) water is great for plants. As to the antifungal treatments, sorry I don't know much about them other than we don't use them in Aquaponics since we don't want to be eating them. Many of the anti fungals are actually antibacterials too since lots of the fish diseases that people think are fungus are actually bacteria. So, I'm sorry not to have much info for you, perhaps a little more info about the treatments you use in your aquarium would help? Is it a copper based treatment? If so, then it might be ok for the plants so long as you dilute it when you water with the aquarium water. Most aquarium medical treatments are not safe for food fish so are also probably not great for a food garden. Here is a link that might be useful: www.TCLynx.com

Dogma is holding firm to the belief that something could neither be a conceptually or practically superior practice because you believe something else seems to be satisfactory - 'works for me'. Old beliefs are like a pair of old shoes - we often value their comfort so much we tend to ignore the fact they're full of holes. Almost everyone prefers the relative comfort of belief to the exercise of reason because believing is easier than reasoning; which brings us full circle to why there are so many more believers than thinkers. My $.02 I'm pretty sure you're not suggesting that a haphazard approach (a little of this and a little of that, even though I know neither what the plant needs nor what I'm giving it) is a superior approach to a well-reasoned supplementation plan. Discounting all reason because we're satisfied with the status quo is self-limiting by default. BTW - if Punky's trees are in pots (don't think that was made clear), moving closer to how nature does things is an exercise fraught with obstacles. Growing in the ground and growing in pots are widely divergent cultures. On a scale of 1-10 with growing in the ground being a 1 and hydroponic growing a 10, conventional container culture is probably a 7 or 8. Al

There are a number of difficulties to work with, besides ammonia production at high pH, you are doing fresh water and roots usually need to be in the dark so a kelp/red algae jungle is out. And without much light the yield of any plant will be bad. Perhaps a raft of lettuce on top near a window and cross your fingers that the fish would keep the roots clean but not eat the tender root hairs (hmmm, something says maybe not, better an aquariast) , and that such a high pH wouldn't be a one-two punch with low light to knock out the plants quickly. The Asians eat a lot of Wolffia duckweed... Spirulina is highly nutritious, but due to the proximity of the fish, things like E. coli, etc., I'd grow it as fish food... The difficulty is you want to adapt your plants to your choice of fish, but people doing aquaponics have enough trouble making it work by adapting the very best fish to plants, both sequestered in their appropriate media. Maybe a Spirulina cage the water can diffuse across but not the algae (30-50 micron = 0.03-0.05 mm =~400 mesh) would be simple and rewarding fun project! If you are really intent, check on the conditions required for watercress and see if you can meet them halfway. Someone else probably knows if this is doable with Watercress or also Chinese Water Spinach both are about as good a compromise as it gets for high pH. Just be careful since some really nasty parasites (alien brain eaters LOL unless it is personal, then SOOL) according to the CDC come from water plants grown in these sorts of environments This post was edited by PupillaCharites on Wed, Sep 4, 13 at 19:28