Nitrite In Fishless Tank

[rhostog]

I've been setting up a 28 litre tank for my daughter to keep dwarf frogs. It's been running now for about 2 weeks, and the plan was to change the water, add some mature media and a couple of small fish from the community tank this week, and then get the frogs in a few weeks.

Before adding the media or fish, I tested the water. Ammonia zero, pH normal. As we have traces of nitrite in our tap water, I was wondering if it would show in the tank, or whether the filter would have started dealing with it - but was very surprised that the nitrite reading was about 1.2. I tested the tap water, which reads 0.1 as usual, and even re-tested the tank, in case something had been contaminated, and it was still 1.2 ish.

Obviously I'm not going to add fish to this , but I'm wondering where the nitrite has come from? Would a few dead leaves on the plants have generated enough ammonia to produce this? Any suggestions for where else it could have come from? I was going to do a big water change, but now I'm thinking I might leave it a few days and see what happens?

The tank has play sand, plastic 'driftwood', a few rounded pebbles which we pH tested (excellent science for a 10-year-old), a plastic saucer, and a few days ago I added 3 plants (a cutting from the community tank and 2 from a shop). It's got a small internal filter with black sponge and some filter floss I added to help clear the water. A heater keeps it at 23 C, and the light is on a few hours a day for the plants. Water conditioner, plant feed, same as I use in the community tank.

 

[5teady_2012]

I dont know what has caused this (possibly the dead plants, but the nitrite seems too high for that)

I would personally do a water change big enough to drop it back to 0, then see what happens.

It may stay stable after that - remove the dead plants.

 

[rabbut]

Plants would easily caurse the nitrite spike if they died back sufficiently.

I'd add the mature filter media and give it a couple of hours before re-testing. That should drop it back to zero for you, and a couple of hours without ammonia won't kill the bacteria Once it hits zero, assuming it has taken less than 48 hours, I'd then add the fish.

HTH
Rabbut

 

[Miss Wiggle]

yeah as rabbut say's, add the media, test the water, if it's not dropped within 24 hrs then start adding ammonia as per a fishless cycle, but it should only take a few days or maybe a week to get it to the end of the cycle.

 

[5teady_2012]

Plants would easily caurse the nitrite spike if they died back sufficiently.

I'd add the mature filter media and give it a couple of hours before re-testing. That should drop it back to zero for you, and a couple of hours without ammonia won't kill the bacteria Once it hits zero, assuming it has taken less than 48 hours, I'd then add the fish.

HTH
Rabbut

I didnt know that, i know little about plants and would not of thought it could cause so much much nitrite, but your never too old to learn new things

 

[rhostog]

There's only a few bits of leaves, broken off when they were planted, and a bit of dead leaf stuck to the plastic ornament - I know it's a small tank, but would be surprised if they could generate that much ammonia? I've picked them out now anyway.

I'm going to do a water change, in case there's something dodgy in there (I dunno, bit of fish food stuck to the plant? dead snail? um... can't see anything...) and leave it overnight, then I'll test again in the morning. If it's up again, I'll know there's still something in there causing the problem and I'll have to investigate further.

Thanks for the advice and support! Much appreciated.