filter necessity and algal blooms

I have a few questions, the first is this.

1. how many filters does a 55 gallon need? Mine currently has 3. a HOB powerhead filter, a canister filter, and a "undergravel" filter. I lost two fishes this week from my 55 (my red longnose dace and my white sucker) when two filters went offline. my canister (which i fixed yesterday after a week and a half of feeling depressed and unmotivated when fall like weather hit), and my undergravel (which is ALWAYS offline as the gravel based air bubblers are constantly knocked out by the fish). I heard people say canisters don't so much filter as polish the water... but in my 55 the canister seems a vital part. When it goes offline fish act funny, get sick, or in this case die.

2. What do you suggest I use to control algea blooms? I have a mass of hair algea on my plants and what I thought was hair algea ended up being black branch algea.

3. my red longnose dace was the most colorful fish in my 55 until it died. can anyone suggest a locally available, non agressive, native fish that could add some color back in my minnow tank?

HOB power filter or just a powerhead? If you have an actual power filter (with bags and maybe a bio-wheel) I would just run that and your canister. The UGF you have probably traps a ton of crap, leading to high nitrate levels. UGF's are worse than nothing IMO, but some folks still use them and they can "work"....unless you are using it as a plant anchor I would pull that sucker out of there and trash it with haste!

If you just have a powerhead (no filtration, just water movement) then I would be more hesitant to use just the canister filter without being able to see it. If it has bio-media, you should be fine. If the canister is just something like a magnum 350 I wouldn't run it solo.

I would do this to control algae:

1. Remove the undergravel filter (UGF)

2. Reduce the amount of food you are feeding

3. Reduce (within reason) the length of photoperiod (keep it at 8-10 hours)

4. Keep fewer fish or smaller fish in your tank

In the meantime remove the algae you have by hand and within time things should clear up. Just my take on it--hopefully it helps.

Edited by Gene2308, 28 August 2009 - 01:00 PM.

1.) You need 0 if you've got something in the tank capable of dealing with ammonia and a way to keep the water oxygenated. The soil substrate tanks some of the members here run seem to be capable of running filterless. Canisters are some of the better filters on the market in my opinion. They're able to hold considerable amounts of media, allow for customization of the media, and move decent amounts of water. They are expensive, but they outperform the cheaper styles of filters in my experience.

Did you test your water levels? If significant amounts of ammonia were present, then the filters that weren't working may have been responsible for most of your biological filtration.

2.) Plants and water changes seem to be the most recommended options. Plants compete with the algae for nutrients while water changes help remove excess nutrients in the water column. If you've got a nutrient problem you may want to consider other things as well. Are you feeding too much, stocking too heavy, or is most of what you're feeding being wasted?

3.) No idea, but I'd be happy to see some pictures of whatever you find.

Oh, I forgot something very important:

If you aren't already doing it, get on a water change schedule of about 25% weekly give or take. More is better, especially if you have a lot of fish, feed alot, etc. I have had tanks in the past that I changed about 30% every 3rd day.