i want your 2 cents about canister filters

From PetPlace.com ... " In general it is safe to say that discus require ultra pure water conditions. You will need to have a water source analysis done so you know exactly what's in the water before you fill the tank. Depending on the results of the water analysis, you may require special equipment/procedures to detoxify the water, such as a de-ionizer or reverse osmosis. Discus require soft, acid water and temperatures kept considerably higher than most tropical fish. Water temperature should be maintained between 86 to 88 degrees Fahrenheit. In times of stress or disease, it may be necessary to raise the tank temperature as high as 92 F. You should make sure you have a heater in your tank able to hold these high temperatures without fluctuation.

Filtration is essential as discus will not tolerate the usual tank pollutants that other tropicals will. Ammonia, a natural fish waste, will kill discus quickly. Oftentimes, a variety of filters plus daily water changes are needed to keep the tank water clean. It is imperative that any excess food and fish waste be vacuumed from the tank to prevent the water from fouling. ...

... No discussion about discus would be complete without mentioning that these fish are very susceptible to parasites. Intestinal worms, gill flukes, fungi, bacteria are common illnesses typically brought on by stress and poor husbandry practices."


While I don't keep discus fish myself, everything that I have heard and read about them indicates that they need really well filtered, demineralized, ammonia free, parasite free water. With $100+ per discus fish invested, IMHO 'standard' canister filters may not be up to the job of protecting your 'investment'. I'd seriously consider going with a modular filter system like Pentair, where you can get 20 micron cartridge filtration, sufficient carbon/resin to absorb all chemical nasties, a powerful UV unit to kill off parasites etc., even though it would be $100 or so more expensive than a 'standard' canister filter. The closest setup I have seen described can be found at http://www.cloudytanks.com/ubbthrea...r/46/page/0/view/collapsed/sb/5/o/o/fpart/all I'd also definitely include separate bio-wheel HOB filtration on the tank.

There are quite a few forums and web sites devoted exclusively to discus. I'd check them out before buying any equipment. Commercial sites often have a vested interest in selling you as much stuff as they can and they often are over the top in their recommendations.

Discus are one of the more demanding FW fish to keep, so be sure to check with as many people who keep them before diving in. Here's an interesting-looking web site on discus:

http://www.dph.nl/

HTH,
Jim

filter cleaning and water changes

While adding filtration is a great idea, discus will also require more water changes and higher temperatures than you probably have now. At higher temps, like 82 to 84 for adult discus, up to 88 for smaller fish that are still growing and need to eat a lot, there is less oxygen in the water so you have to stock less fish -- figure 10 gallons per discus or more. If you are doing water changes only once a week, you probably need to stock 1 discus per 20 gallons.

Personally, I'd add the new filter and keep the old ones also. I run a HOT 250 and a Penguin 330 and a HydroV on a 105 gallon discus tank. On the other discus tank I have an Eheim Ecco canister and Eheim 2026Pro2 canister, for 58 gallons.