Help! My fish tank is green!

Hello lovely ladies

I'm having a tough time keeping my poor fish clean! I change about 15% of their water weekly, vacuum the gravel/pebbles, there is a filter in the tank and they get fed the correct amount so food doesn't settle and rot. I also clean the walls with one of those magnetic scourers.

Does anyone have any ideas for keeping a tank green-free? I'm thinking I may need to take out most of the water (or even all!) to get them clean :(

I would say that it would mean that you have your fish tank near too much natural light... Its would be a good idea to give it a good clean out ( no soapy water ) just put fish in another container with about 15% of the tanks water, and give the tank a good clean, its a good idea to put in a few drop of stress coat into your tank before you take your fish out, kinda numbs them a little while your cleaning the tank and dont forget to give the stones a really good clean...

how big is your tank, you might have to get a filter if you dont already have one... other wise a snail is always handy think to have in the tank, as they love to keep you tank clean for you...

just noticed you said it has a filter, its proberly time to replace the carborn and chacoal in it... plus it would be a good idea to go to a aquarium and make sure its the right size for your tank, sometimes with package deal tanks that come with everything are given a filter too small for the tank( that way you will have too keep coming back for more fish when they die or replace the filter either way its win win for them ;)

Thanks Tali :)

They are in a bright room, not in any direct sunlight though. It's a 50L tank with a good filter. I like the snail idea, I'll just have to check if they can go in the tank, as some of my fish aren't very friendly!!! We were told when we got them that they will pick on slow-moving fish and snails...bullies.

hey hun, i wouldnt remove all the water from the tank, you'll take out all the good bacteria with it, try a 25% change instead of 15% and see how u go.
Algea build up is usually cause from too much light, like all plants they grow because of it.
What kind of fish do u have? have u tried throwing in a few bristlenose catfish in? they're awesome algea eaters, i'd reccommend get some 8cm ones, the babies dont tend to do too well.
its a pain with smaller tanks, even though u have everything u need to keep it clean, its still alot of work!

Thanks Skybie, we have danios and paradise fish. The PF are the mean ones!

yeh they're pretty nasty!!
BN are fairly good at comoflaging themselves though. you can only try and see how they go, they're no expensive

Brilliant, I'll get the aquarium guys to help me pick big ones!

As long as your fish are not dying, a green tank means a healthy tank but it is not attractive to look at! Too much direct light could be causing this, as someone mentioned get some bristlenose cat fish or even sucking catfish. 25% change of water each week. Try to steer clear of the 'algae eating' potions the pet shops will try to sell you, the less you need to add in the way of medications, the better. If you have a heavily planted tank and not enough filtration this could also be causing your green tank. Cellophane filters the sun, so you could get some of that and wrap it around your tank for a week or 2 and see if that makes a difference. My tank is not in any direct sunlight but still gets a green tinge to it. Good luck

Have you tested your water for phosphorus? Phosphorus is added to aquariums through fish food, some plant fertilizers and some pH buffers. Phosphorus encourages algea growth and if the levels get too high, can be toxic to fish. I struggle with phosphorus levels and have now switched fish food brands to a low phosphorus brand. This is having a slow effect at getting things under control.
Good luck
FG

PS - good aquarium stores should be able to test the phosphorus levels for you so you dont have to get a test kit!

I'll give that a go Farmgirl, cheers! We do just have a cheap food so it could be the issue...

I know this might not apply to your tank, but when we had our salt water tank, doing too many water changes too often, can sometimes be just as harmful as not doing a water change, as you remove all the good stuff along with the bad stuff.

If you are testing the water, maybe testing the water you are filling the tank with also? And make sure you are adding the correct amount of water conditioner to the water and not overdosing it as well.

But, like the others have said, may be a little too much light, and if you can knock back the food a little, see if that helps maybe?

OK! I think I may have located the source of the problem! I did a full tank clean today, took out all the water, cleaned all the ornaments, the pebbles, everything. And I found...the catfish that went missing a few weeks ago :redface: Poor little fella! He was under one of the bigger ornaments, so I didn't see him when I was vacuuming the pebbles in the water changes.

Anyway, hopefully the water won't green up so much now!

You could also try briselnose catfish, they like to eat the green.
Do you clean the filter under running tap water or in the syphened tank water? I suggest tank water as this would preserve the natual (good) bacteria.
Are you feeding you fish every day? if so try every second day. Most ppl think they don't feed too much, but most do.

I'll try cleaning the filter with syphoned tank water from now on, cheers for the tip!