Cycling in Fry Tank

[bigfish]

Hi

I got a 20 litre tank that i'm currently using as a rearing tank for guppy fry, it has no gravel or ornaments just some floating plants and has a bio-foam filter in it but my water parametres have gone hye wire!!!!

my nitrite level is 2.0 mg/litre and only reaches 0.25mg/litre after a 50% water change my Ammonnia is currently at 0.4mg/litre.

I've been adding a culture to the water (King British Safe Water) which has natural bacteria in it, but i can only add it once a week

So tried bio-start culture instead but that aint working either.

So what am i doing wrong?

If i changed 80% of the water the readings go to safe zones but after two days it's back up to critical.

I've added aqualibrum salt to the water to reduce the toxic affect on the fish.

Am really worried.

HELP

 

[Elisabeth]

80%? Sounds like you are changing too much of the water at a time and the tank is crashing. Changing 80% will remove a lot of the good bacteria which will live in the water as there is nothing in the tank, ie gravel.

 

[Kryten]

You need to do frequent small changes like 10% every other day, as even 50% in one go is too much. This allows bacteria to multiply but stops the water from going stagnant. Also, it sounds like you've used two chemicals at the same time, this may not be doing your water any favours

 

[playfulalliecat]

Maybe you have posted previously and I am missing something but how long have you been cycling this tank? Do you have any fish in it, guppys now or preparing for the guppies?

When cycling a tank you need to have a fish in it to feed the good bacteria for the nitrates. We use StressZyme but put fish in it to make the ammonia, which makes the nitrites, which make the nitrates.

I know a lot of people talk about fishless cycles but they are using food in small quantities or adding ammonia to it that they get from the lfs or lps. Not real sure about this as we haven't done it. Right now we are in a good position to speed up our cycles by using gravel and filter foam as well as water from existing tanks. The joys of having more than one, means you can help the others along too!

Also that kind of water changing is definitely crashing your cycle. If the tank is under a month old with no fish then don't do water changes. If it has fish then do small 10% and no more but no more often than absolutely necessary for the health of your fish.