Time to change the media...

[pesto]

Green water after installing 2nd fish in a 10g tank. Tank has been set up for one month with one molly, added cory cat and green water two days later. I haven't changed the filter media, or cleaned it. I can never remember which one I should do...clean or change? If clean, just run it under tapwater, right?

Thanks

[anonapersona]

Rinse in with tank water, and do a water change while you are at it.

Remove 20 % or more of the tank water to a bucket and swish the filter cartridge in that. Clean off everything that you can, and dump the water remaining the filter case or it will blow trash out when you start.

While you are cleaning, remove the impelller and scrub it with a filter brush or dedicated new toothbrush. Check for stuff wound around the shaft, remove with tweezers if necessary.

Put everything back together and fill the filter with tank water, then dump the old dirty water -- in a plant would be nice. use the bucket to draw some tap water, correct temp please, dechlorinate and add to the tank, gently.

You can get away with doing this several times before it requires a new cartridge. If the water gets particles in it that you can see, you might need the new one. You'd want to cut off some of the mesh stuff from the old cartridge to put alongside the new cartridge to help transfer some of the bacteria.

[Hebdizzle]

what type of filter is it? If it is a HOB, yes, you should have changed it within the one month. People often wash it out in tank water during their weekly water changes. Also, I would reccomend getting 1-2 more cory cats because they are a schooling fish. I have 3 in a 10 gallon and they clean up the bottom of the tank wonderfully, and are very peaceful. They need to be fed either sinking tablets, frozen or live worms. Shrimp pellets are also a favorite for mine.

Other questions to ask :

1) Is the tank in direct sunlight?
2) What type of lighting do you have? the photoperiod?
3) Do you have live plants?
4) Do you do waterchanges?

Aaron

[anonapersona]

You are probably still in the midst of cycling, and the doubling of the fish load has stressed the filtration. With this in mind, take it easy on cleaning the filter right now. All the more reason to rinse and not replace, you can't afford any harm to the bacteria now.

Reduce feeding - this will let the bacteria catch up on the wastes in the tank.

[pesto]

Hehe thanks for the posts, I'll go ahead wash it as recommended. I'm not overfeeding, and the tank isn't cycling, I cycled it before I added the first fish :).


Thanks everyone!

[anonapersona]

How did you cycle the tank before adding fish?

Do you have test kits that can measure the ammonia and nitrites?

Whatever bacteria you had going, by whatever means, would have died back to the level needed for one fish. Now you have two. The bacteria need to double, and they will, but they are slow.

While the bacteria are still trying to catch up, you will need to do some water changes. If you have test kits you would know how large and how often they should be.

Can you test the water and post those results?