Brown algae frustration! (Goldfish tank) - Algae

abnormalsanon · 09-26-2007, 06:11 AM

I have had an ongoing battle with brown diatom algae in my goldfish tank for going on 3 years now. It's the dusty kind, not the slimey stuff, and while it brushes off easily it literally coats every surface in the tank. I have never had this problem in any of my other tanks!

The tank is 55gal and I have 130w light over it for 7 hours a day. Ammonia and nitrite readings are always 0, and nitrate is generally between 20-60ppm. I have two Eheim 2213s running on this tank and CO2 injection using the mist method (no reactor, I am working on that). I am dosing PPS Pro daily, Excel 2 x week, and have been using the PPS Pro method for about one month. My plants are tough slow growers (anubias, java fern, and crypts) but I also have water hyacinth to suck up excess nutrients.

I have three golfish (two are small) and two weather loaches in the tank, along with an assortment of snails (apples and ramshorns). The tank as it is now has been set up for 3 months, but prior to that it was set up for a full year with the same problem.

Over the years I have tried many types of set ups and methods, trying to give each one a chance and see what happens: no plants, heavily planted with fast growers; unfertilized with no CO2, EI and PPS Pro with CO2 injection; and photoperiods varying from 6 to 9 hours. No matter what I do, the brown algae eventually returns.

I've heard that high phosphates can cause brown algae problems, and while I don't have a phosphate test kit, I do 50% weekly water changes religiously, have some water hyacinth to suck up excess nutrients, and make sure the food I feed does not contain phosphates. I have also heard low light can cause the problem, but I have 2.3wpg which is technically medium light.

I can't add otos or SAEs since it's a coldwater tank. I've heard some people put plecos in with their goldfish to control algae, but that doesn't seem like much of a solution and again there's the cold water issue.

I am truly at a loss and so tired of throwing money at this tank and ending up with the same result. Help please! Any new ideas?

hoppycalif · 09-26-2007, 08:11 AM

You have 130 watts for 55 gallons, or 2.4 watts per gallon, but only grow low light plants. Algae, like plants, grows in response to the light intensity. Those two facts tell me you should decrease your light intensity by close to half. Also, it would help to use a drop checker so you will know that you are supplying adequate CO2. With much lower light intensity you may not even need the CO2, but it is always beneficial even in low light tanks.

abnormalsanon · 09-26-2007, 09:20 AM

Thanks for the reply, hoppy. Unfortunately, I've tried adding medium- to high-light plants in the past with the same result. I also have some water hyacinth which is very fast-growing (doubles in size about every week or two) and blocks out some of the light.

I agree that I need a CO2 drop checker and have one on the way. I suspect my levels are not good enough right now and want to buy/make an inline reactor eventually.

I know there's no clear cut answer here, so i appreciate the reply!

Carissa1 · 09-28-2007, 02:55 PM

Why not try removing one of the light bulbs? You don't have much to lose.

Excess silica can reportedly also cause this problem. Do you have sand substrate? If so it's possible that it's leaching enough silica on a regular basis to keep the diatoms growing.

NeonRob · 10-01-2007, 07:08 PM

I had a newly planted low tech tank with most of the glass covered in brown algae like you are describing. I bought some otos and they wiped it out in 2 days.

abnormalsanon · 10-02-2007, 03:11 AM

Quote:

Originally Posted by rwoehr

I had a newly planted low tech tank with most of the glass covered in brown algae like you are describing. I bought some otos and they wiped it out in 2 days.

I do love otos, but this is a coldwater tank so I can't really add them.

I scraped the glass today, but rocks, plants, and driftwood are still coated in the stuff. Would anyone recommend use of a diatom filter? I know it doesn't solve the underlying problem, but maybe it would buy me some time.

gotcheaprice · 10-10-2007, 12:38 AM

I've been having brown algae in my gf tank for the longest time too. 40 watts, with a hob whisper filter. I dose seachem excel and comp once a week since it's not heavily planted. It's right next to the window so that might be the problem, but other than that. i've been over run with it all the time. considering getting a oto, but not sure about temps(i don't use heater since I'm in hawaii, temp stays consistent)

k-maub · 10-10-2007, 04:50 AM

If I may make a suggestion, perhaps try decreasing the frequency or magnitude of your water changes. Like other have said, silicates can contribute to diatom algae formation. I won't claim to know exactly what goes into my tap water, but if you stop giving the diatoms a fresh supply of whatever it is they enjoy in the tap water (silicates, I guess), they should run out their course when that nutrient is exhausted.

BTW, I'm philosophying on the mechanisms, but I speak from experience that cutting back on the 50% weekly water changes resulted in dramatically less brown algae for me. I have never kept goldfish, though, so maybe they produce too much waste?

gotcheaprice · 10-10-2007, 11:37 PM

I'm gonna get more plants, bunch of hornwort of anacrias maybe just to temporally increase my plant load till i get my ahsupply light so i can get higher lights.
And my water changes are at 40% every 2-3 weeks. I'm gonna redo my substrate and scrub it clean this weekend maybe so it'll be 2 weeks this time.