Problem with Nitrite level

[Shadowfax]

Hi, I have a small hexagonal 5 gallon fish tank, it has an under gravel filter and 4 Mollies. The tank is about 4 weeks old and the PHP levels have been right from the start (7.5mg/l) but the nitrite level I just can't get right. The test comes out at around 2.5 mg/l my chart says just keep adding the filter start live bacteria. I feed the fish once every 2 days and add a little filter start at the same time. My ammonia result is 0.0 mg/l. I have started to do 10% water chage every week to get it down.

What should I do?

Andy

 

[Sasha]

Did you cycle the tank?

I would do a 50% water change and see if that brings down the nitrites.

 

[clutterydrawer]

what's php?

read the pinned topic in this forum called "avoiding and treating new tank syndrome".

 

[luxum]

I think "PHP" was a typo for Ph. What's happening is that the nitrogen cycle in your tank is establishing, hence the high nitrites. Eventually the bacteria in the tank will catch up and the nitrite level will drop to zero. At that point you'll need to pay attention to the nitrate levels and dilute them with regular water changes, 20% each week. In the meantime, you should 20% water changes every day to reduce the nitrites which are toxic.

Now, a word on your stocking. 4 mollies are really not an appropriate stocking for a tiny 5 gallon tank, way too much bioload, not enough swimming room for the mollies which get too big for a little 5 gallon hex. You'll do much better if you return them and get something like a few male guppies or a betta.

 

[Shadowfax]

Sorry I meant PH php is my web language (force of habit).

ANdy

 

[Shadowfax]

AT last! my Nitrite level is down to 0.1mg/l t's almost clear, I have been doing a 15% water change evey 2 days this week. At the begging it was 2.5mg/l a very dark purple colour.

1.) Right how often & how much should I now keep adding the filter start (bacteria)?
2.) How often & how much should I change the water?
3.) What small fish is good for gravel bed cleaning?

Thanks inadvance for your help

Andy

 

[TorPeteO]

Good work! I'm glad to hear that your level has become nearly stable.

1) If you need to add the filter start, just follow the directions on the bottle. Once the tank is completely cycled (ammonia and nitrite stay at 0), there's not really any need to add it anymore.

2) In a 5 gallon tank, it would probably be your best bet to do one 40% water change a week, or two 20% in a week. You don't necessarily have to keep that up, but such a schedule would be ideal.

3) Corys are good for gravel cleaning, but they require a shoal, and a 5 gallon tank couldn't support one. I'm not sure what kind, perhaps if you could find a frewshwater bumble bee goby they could help keep the tank clean. Make sure it's freshwater, though, as there are also brackish water species.

Just a small tip, pH isn't measured in mg/L or ppm or anything, it's a measure of magnitude and it hasn't got a unit.

 

[Shadowfax]

Just want to say that was a nice friendly post, I will sure follow your help. Hope to speak to you again if I have any problems in this learning process

Andy