Aquarium algae question

I’m still fairly new to the aquarium world, so I’m hoping someone out there can help me.

I’ve had my 20-gallon aquarium for about a year now. It had cycled nicely, and everything was fine up until a few months ago. I had to leave town for a handful of days, and I purchased one of those auto-light switches that turns the lights on and off at specified times. I tested it, and it seemed to work okay. But when I got back home from the trip, it had failed at some point. I’m not sure how many days the light was left on, but I’m guessing a few. There was a growth of brown algae on everything: the glass, the artificial plants, and some of the decorations. I scrubbed the sides and washed off the plants and decorations, but ever since then, the brown algae continues to come back, no matter how often I get rid of it.

I’m assuming this was due to the lights being left on for so long, but I suppose it could just be a coincidence that it started at the same time. Any confirmation that this could have been what started it, and more importantly, any idea on how to get rid of it once and for all?

Oh, I should add, it’s a freshwater tank, if that makes a difference.

What sort of fish are in it?

Try a water treatment, available at any pet store or retail chain such as Wal-Mart or Target. Even supermarkets have a small assortment.

You also may want to invest in a pleco fish. They’ll eat the algae and will not bother the other fish in your tank.

Right now, just five zebra danios. I’ve been planning to add more (I had a few others types that died a while back), so perhaps starting with the pleco you recommended would be a good thing to do.

I’ll hit a pet store today and look for the pleco and water treatment. Thanks for your advice!

What sort of water are you using? IIRC plain old tap water isn’t the best thing for aquariums. Too much in the way of phosphates.

Yes, I use tap water, but always with a tap water conditioner before I add it to the aquarium.

A few things:

  1. Try a phosphate remover. They’re little packs you can just stick in your fliter.

  2. Turn the lights on your tank off and cover your tank in a blanket. Make sure NO light gets in. Leave the tank like this for a few days.

Do you have live plants?

Nope, no live plants, just fake ones. Should I toss 'em and start over?

Thanks for the other advice. I will try that.

Erm… when you say “NO light”… does that mean I shouldn’t even lift the blanket to feed them for those few days?

I’d recommend live plants, as well. You don’t necessarily need to trash the plastic ones, but you may want to clean them well. Don’t use soap, just rub off any slime that may be on them under running water. For live plants, don’t crowd the tank with them. If that means taking out the plastic ones altogether, that’s fine, too. I bought these pod like things that float on the surface, and the plant germinates from that. If it get’s too crowded, just trim it. Not only will the aquarium get oxygen, but some species of fish nibble on the roots, and seem to like it.

Clean the tank using one of those vacuum-like things (you can get them cheap, too, at a pet store or W-M). It sucks all the fish-crap from the gravel on the bottom, but it’s not forceful enough to suck up the gravel completely.

Change your trap in your filter. Let the water cycle for a few days, then change it again. It may seem like a lot of trouble, but it’ll get some of the stuff floatin in the water.

You definately have to treat the water first. Keep a treated gallon handy to refill when you need to (evaporation, etc).

Make sure your thermostat and heater are working. I seem to recall that if the temperature fluctuates too much, it kills your fish, and encourages algae growth.

You don’t have to black out your fish 24/7 for those few days. You can take the blanket off to feed them, just put it back on when you’re done.

Good luck, and enjoy your fish. There’s nothing more relaxing than sitting quietly and watching them swim around. The hum of the filter and gentle splashing of the bubbles is also quite soothing.

The brown algae would be diatoms, and spores of many kinds of algae will always be present in the water - so forget about removing the source. There was simply an imbalance of light/nutrients that allowed the diatom cells to kick their growth into high gear, and it will most likely pass with time. The thing not to do is to make radical changes to water chemistry in an effort to erradicate them. It may work, but you’ll be just as likely to cause a similar upset to the “ecology” of the tank that allowed them to get going in the first place.

There are a lot of web pages that describe varying conditions under which different types of algae grow best; an example being when the flourescent lights get old (like a year or two) they emit a slightly different spectrum, which may favour some types of algae. Take a look through the various pages to find the cause if you like (could be extra light combined with less nutrients entering the water for the five days… something else maybe?) but you’ll probably end up doing the same thing to alleviate the problem, so that info’s mostly for personal interest.

If the tap water you were using before never led to any problems for over a year, you don’t need to condition it any different than you always have. Any bad nutrient balances would have shown up long ago, but naturally many pet shops will try to push a lot of special water conditioners on a guy that aren’t neccesary (can’t blame them, they are running a business).

Once I got to know what I was doing, I’ve never needed any chemicals to keep my tanks running fine. If I had a diatom problem, I’d scrub it off everything I could (and suck up the loose bits with the hose). I’d probably then do 25% water changes every few days until things cleared up (don’t wanna rock the boat too much with total refills), rubbing the diatoms off every time. Algae eating fish may eat the diatoms, but unless they’re really hungry I’ve found they don’t really like eating them as much as the green algaes. Live plants can help; I’d suggest some duckweed . It’ll compete for the nutrients, and floats on the surface cutting down on light getting down to the diatoms. It’s also damn near impossible to kill so you don’t need any skill in aquatic horticulture. You can always skim it out quite easily if you don’t like it.

The blackout lighting may help too, I’d say try it if you like. Zebras are tough little bastards, they should be fine. Do give them a little food daily though, mine don’t do as well as other fish when starved (very small and ridiculously active).

As someone said, Plecos are great for keeping algae down. But, eventually they’ll need supplemental algae for food. The amount in the tank won’t be enough to keep them alive, and they don’t do well with the flake foods for other fish. You have to give them algae tabs. They also love sliced zuccini.

Opening the tank to feed the fish is fine. By “NO” light I just mean make sure the lights are off and its dark inside. No ambient light, no sunlight (especially no sunlight).
Siamese Algae Eaters are probably the best you can get if you want a fishy solution. Make sure you get REAL SAEs though. I don’t have a link off hand that shows how to distinguish them but I can find one, or maybe someone else can talk about it.

Chemicals and filtering the tap water you are using will both defiantly help. Chemicals are hard on Biological Filters though. There is a piece of equimptment that will naturally stop your algae problem from ever returning. It’s called a “Protein Skimmer”. It removes the organic matter from the water that most algae thrive on. They can get rather expensive for new designer brands but, I am sure you could find one that suites your tank size for under $50. A used one will obviously co$t even less. Along with reducing algae problems it reduces the overall stress on your filters not to mention your critters. I know people that run marine “Reef” tanks solely with the use of a efficient protein skimmer.
Good Luck

I went to pet store earlier this evening. I didn’t see anything specifically labeled as a ‘phosphate remover’ or the equivalent. I did pick up some tablets called “No More Algae”. I dropped two in per the instructions; we’ll see how it works.

The lady at the pet store highly recommended Chinese Algae Eaters when I explained my problem to her. I got two, but after getting home and looking them up at some sources, I’m thinking perhaps she led me astray; it sounds as if they’re good for what I need when they’re young, but when they get older, they stop eating the algae and become aggressive towards the other fish. Well, they’re in the tank now. Did I do wrong?

Thanks for the advice, everyone. I am going to seriously consider live plants. I’m going to give it a few days, though, and see how the algae-b-gone tablets and the Chinese Algae Eaters do. I’ll look into the Protein Skimmer, but at the moment, I don’t have a whole lot of money to spend. So maybe a bit down the line.

Thanks again for the advice, everyone.

You don’t want Chinese algae eaters you want Siamese algae eaters. The problem is other algae eaters are commonly labeled as Siamese, or you are incorrectly informed that what you want are Chinese algae eaters.

Here Trigonal Planar, take a look… this is the fish I was sold. Is it completely the wrong thing?

Take the Chinese algae eater back! They’re very nasty.

Plecos are very nice, they can grow very big–I had one that was less than an inch when I bought it, and grew to be a foot long. I have a soft spot in my heart for them. They do need more food than just the algae in the tank, but they’re very endearing fish. (Okay, so I’m strange).

You might want an otocinclus (not sure if I spelled that right). They stay small, they never bother anybody, they eat algae. See if you can find one.

Here’s a link to pictures of otocinclus, and some info. They’re really nice, peaceable little things.

I have a soft spot for plecos as well. I had one that got to be as big as my hand. He may have looked slow but he was nearly impossible to catch on the rare times I had to remove him from the tank. He was also quite fond of jumping out of the tank. He would sort of “walk” across the tile floor on his fins. One day I came home to find him just lying there on the floor as dry as leather and I thought he was surely dead. I picked him up and put him back in the tank and within a few minutes he was firmly attached to his favorite spot just sucking away.

My kids used to love to walk up to the tank and point at him and say “YOU SUCK”. It would crack me up.

Mean ol’ Chinese Algae Eaters returned to store. Store did not have an otocinclus. Plecostomus purchased, and awaiting equilization of water temp to introduce him into the tank.

I’m intrigued by the idea of feeding him zucchini. How does that work? Just drop one thin slice in?