Brown Algae Issue

NorthcoastGirl

Proud Fish Geek
Oct 28, 2009
138
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The Rust Belt
Hello, new to the forum and relatively new to the hobby itself. =)

I've had my 20 gallon planted tank for about a year now. It has 12 red phantom tetras and 5 peppered cories. My water perimeters are always good, I do regular filter maintenence, I change about 30% of the water 3 times a week. The fish are active, healthy and beautiful. All is well, EXCEPT for this tenacious brown algae that creeps up all over the walls and all over the leaves of my Amazon swords! I try to rub the majority of it off everytime I do a water change, but it keeps coming back. Removing it from the glass is no big deal, but I'm afraid it'll block photosynthesis on the leaves. Not to mention that it looks bad.

Am I doing something wrong, here? Maybe changing the water too much? The swords do a great job of out-competing any other algae but the brown stuff is a real pain. My tank is very low-tech- no C02 and no fertilizer. The plants themselves seem to growing well except for the leaves covered with algae. It's a frustrating, because my tank is healthy ( or at least it seems to be) but the algae ruins the whole effect! I'd have posted pictures but I'm ashamed of the algae! =(

Has anybody ever had this problem, and if so, what was the solution? An LFS salesperson recommended snails- are there any aquatic snails that don't breed into the thousands? ( we already tackled a prolific snail episode earlier this year ).


Thanks for any feedback, ANY is appreciated~
~ncg
 
Normally diatoms pop up in new tanks, but a year old tank should be past that point.

What is your lighting like? Sometimes low lighting can become an issue.

As for snails, nerites may be an option as they will not produce in the normal tank settings. I am not sure how well they do with diatoms but I have heard they are good with other algae types so I would assume they would work.
 
Diatoms are frustrating. They don't only pop up in new tanks. They're actually not an algae. They're a shelled animal that grows from a combination of silica and phosphates. They're frequent in new tanks because of the silica. What are you using for a substrate? That can often create a bloom as well if it has high silicate content.

When I got a new tank last year, even though it had been used for 10 years prior to me getting it, I had diatoms like I've never seen. It was an acrylic tank too! I determined it was the rocks and I was using, in combination with high phosphates in my water. Eventually, the items leaching the silicates will stop producing as much and it'll go away, but that can take a while. I got through my routine of brushing every leaf and surface in a heavily planted 150G every 2 days (AHH!!!) by using phosphate removing filter media. It actually did a very good job. I could tell when it needed replaced because the diatoms would start coming back. You also need to make sure you vaccuum all the diatom "dust" out of the tank. Even if you use phosphate removing media, as they die and their shells break down, it creates more silica and phosphate resources to continue the cycle. Brush it off, vaccuum it out, remove the phosphates.

In addition to that, I've found mollies LOVE DIATOMS. After I got mollies, every single diatom in the tank was picked clean and I haven't seen 1 little spot since LOL. I've even been able to stop the use of phosphate media.

and I would actually cut down on your water changes. You're changing a LOT of water, introducing MORE phosphates every time you do.
 
I currently have diatoms in my tank but there are so few and they are only on this one fake rock I think It looks good. I have found that otocinclus LOVE them and keep my tank very clean. I agree with NorthcoastGirl about the water changes. You really should only be doing one 50% water change a week or two 25% water changes a week. I haven't found any snail that does a good job of eating diotoms, yet. Many snails eat them but most will eat your plants too. The snails that don't eat plants often wont cure diatoms. If you have decor that dosn't have live plants on it you can take it out and let it sit in the sun for a day. Then put it back in the tank and they shouldn't re-colonize it.
 
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Thanks for all the suggestions. =) I feel silly- here I was thought I was "doing the right thing" by doing frequent large water changes! My substrate is a basic red flourite, that's it. It's really interesting, though, that the ugly brown stuff are actually little micro animals- makes me want to drag out my daughter's microscope.....


Next time I visit PetSmart, I'll take a water sample so they can check for phosphates, if they can. And maybe get a few otos as well- but would that overstock my tank? It has 17 fish already. The red phantoms are small, but the peppered cories are full grown, almost two inches of stocky, constantly eating fish.

Now that you mention it- my tank is a bit on the low-light side. The lights are just the flourescent ones that came with the tank last year. I never changed them because the plants seemed to grow well. ( My 4 Amazon swordtails are huge, they're on the verge of taking over). The overall lighting is a bit dim because I was trying to get that subdued blackwater look.

I'll definitely look into the phosphate remover and tone down the water changes. Guess I got a little overzealous. :o
 
Frequent water changes are important, just not that frequent. I would recommend weekly water changes.
 
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If the product actually removes phosphates ===> unhappy plants.

Most snails will not eat plants unless the plants themselves are already dead or decaying. I never had issues with stock lighting and diatoms, past the 6-8 month phase.

IF phosphates are the culprit, adding more plants and toning down the weekly changes would be the best solution IMO.
 
That totally depends on how high your phosphates are. Yes, plants need phosphorus, but you can certainly have an excess of it. I use co2 and dry ferts in my tank, never dose phosphorus, and used the remover for a long time with no negative side affects.

Also, many of the phosphate removers also remove silicates, which is the MAJOR culprit of the diatom.
 
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I say your lighting is way too low, just add atleast one more strip light, and do not add anymore plants. see if that helps. along with weekly w/c 's /
 
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