Reader's Comments

Another canister filter worth considering is the Rena Filstar Series. These filters run quietly, work well, and are easy to maintain. They probably are not as good as the Eheims...but they are less expensive and many Fish Store carry them.

-- Will Hoerl, March 13, 2003

I've been keeping fishes for 20+ years, including breeding pedigreed goldfishes, bettas, cichlids etc. The easiest and least maintenance filter I have is my present setup: none. ... actually it's java moss (tons of them) in a 100 gallon tank. I change the water once a quarter, and the only maintenance I do is to refill water lost to evaporation and to remove excess java moss. I know the latter is excessive when the fishes can't swim around but are trapped by the moss. The fishes are low maintenance fishes like comets, shubunkins caught from my pond with plecos and some SAEs.

-- Frank Snow, September 27, 2004

It's mentioned that planted aquariums require less surface agitation however not mentioned is the fact that plants USE oxygen when the lights are out. This is well known and I have first hand experience of this, fish happy during lit hours are at the surface gasping for air once the lights are out. You need to ensure that for a healthy balance of fish/plants you either have a extra aerator running when the lights are off or have significantly more surface agitation 24/7. This however has a knock on if you are dosing CO2 (if you are not running a solenoid to turn it off at night I hope you are not keeping any livestock). I found it best to up the CO2 until it hit optimum levels (30-40ppm) and maintain plenty of surface movement day and night. I have to refill my CO2 a bit more often but my local fire safety center fills them for less than ý10 and has supplied me a few old ones they've acquired for peanuts, end result I have 7 canisters which I get refilled all at once and last ages.

-- Chris Ross, March 2, 2016