Help! High nitrite!

[sagar77]

Today I found out that my tank had slightly high nitrite (about 1ppm). What might have caused it and what is the safest way to reduce it?

Background: I have a 29 gallon freshwater tank with about 30 inches of fish in it (5 dwarf spotted corys, 3 brilliant rasboras, 3 platys, 2 dwarf Gaurami, 1 cherry barb and 1 mystery snail). The tank has gone through cycling and has been established for about 8 weeks. I do regular 15% water changes bimonthly and change the filer cartridge (keeping the same frame) monthly. I feed them a small amount of flake food and sinking shrimp pellets twice daily. I feed the snail an algae disc once daily. My water Ph was low earlier (6.4) and I used PH-up and it went t too high (8) but by regular water changes it has now stabilized at 7. I've had just 2 fatalities (a fancy guppy and a rasbora). The fancy guppy died within a week of purchase.

My other question is concerning the way my rasbora died. One morning I woke up to find that one of my rasboras had a missing tail fin! My tank so no aggressive fin-nippers so this was odd. It died the next day. Can you tell me what happened to its tail fin?


Thanks and let me know if I can be of any help to you!

 

[Cafe Jeff]

Perhaps by only keeping the frame you are losing too much beneficial bacteria and are starting a mini-cycle. As to the Rasbora, I am sorry I can't help there. Jeff

 

[BrianNY]

It is possible that after your tank cycled initially, you added too many fish too quickly. This would have caused another cycle to occur. What type of filters are you using? Perhaps you need to increase the bio capacity of your filter.

 

[Menagerie]

I do regular 15% water changes bimonthly and change the filer cartridge (keeping the same frame) monthly.

Increase you water changes to weekly or every other week. Also, remove 20-30% of the water when doing these changes. As for the rasbora, that may have been caused by the high nitrites, or after his death, the other fish had a snack :?

 

[sagar77]

Well I am using a Whisper poerfilter for 30 to 60 gallon tanks. Will it help to keep some of the carbon from the old cartridge into the new one to 'seed in' the new cartridge?

My question about the rasbora was: One day I found it without its tail-fin. There are no aggressive fish in the tank. What could have caused it?

 

[Menagerie]

My question about the rasbora was: One day I found it without its tail-fin. There are no aggressive fish in the tank. What could have caused it?

It's a long shot, but the nitrite may have caused it. I can't tell if he was found dead or alive, but if he was dead and missing his dorsal fin, more than likely the others may have eaten it. Fish are opportunistic feeders.
You may find this site helpful:
http://fish.mongabay.com/diseases.htm

 

[sagar77]

Thanks for the replies! This is really a prompt and helpful forum. Love it!

I should have probably specified that my rasbora first lost its tail-fin and then died later. It did live for a day without its fin. Which fish could have caused it? Or did it just atrophy by itself? Was it due to high nitrite?

Well, I will take the suggestion of changing 20% of the water weekly. Hopefully the nitrite will come down.

Two more concerns: I have 5 spotted corys (julii) in my tank. They say I need atleast 6. Is 5 not 'good enough' or do I definitely need to add 1 more?

Also, I added a dwarf gaurami to the tank a few days ago. The dwarf gaurami that was already in the tank is chasing it around. This gaurami does make aggressive dashes towards my oher fish too sometimes but has never done any harm to any. Is this normal behavious? Will it hurt any fish?

You guys know the fish I have in my tank. Do you think it is a tad overstocked? Will that be too much of a hassle?

Thanks for all your help!

 

[pkremer]

You might be well-stocked, but it doesn't seem that you are overstocked to me. If you are way overstocked, usually someone will say something even without your asking..

First of all, I don't have any experience with dwarf gouramis, but I do have a blue gourami, and I can tell you that gouramis in general are VERY territorial fish. My gourami began to establish dominance of the tank the day I put him in and still at feeding time continues to let the other fish know who's boss. Everyone has learned how to get away from him, which curbs his aggression a bit. But now your gourami isn't the only guy on the block. You have added a rival, and I don't know if a 30 gallon is enough for two gouramis to set up territories. If they are both male, you may want to consider taking one out.

Also, I don't know why this is the case, but fish are often different when you are not around. When I am in the room, they come to the front to beg for food, but one day I was taking a nap for several hours, and woke up, and just kind of slowly rolled over and watched and I was surprised how some of my fish were acting! They were doing things I had never seen them do before! Gouramis aren't really nippers, but maybe he was going after the rasbora, and the rasbora didn't get out of his way fast enough!

Another idea (and someone correct me if I am wrong). I have heard that cherry barbs like to be in groups of 6 or more. Is it possible that the cherry barb might have been bored with no friends and started being aggressive and nipping the rasbora? I know tiger and rosy barbs will exhibit this behavior if there is only one.

Paul

 

[BrianNY]

The most common mistakes that inexperienced fishkeepers make are adding fish too quickly, and compounding the problem by adding the "wrong" fish.

If you add fish before the tank has fully cycled, you risk taking the cycling process back to square one. As Paul just said, gouramis can be very territorial and thus aggressive. Especially 2 males in the same tank.

I once kept a pair of Giant Gouramis in a planted 55g for over a year with no problems. One day they decided that one of my large black veil angels was no longer welcome. They completely removed his magnificent tail. Fortunately it grew back.

 

[mattrox]

Tail fins are very delicat and can decompse very quickly after a fish has died, especially with the help of a few nibble from other fish. Was the tail fin gone before or after death?

I agree with Managerie about weekly water changes. Most fish can handle a range of pH levels as long as the pH remains stable. Don't worry too much about pH adjusters. Make sure water quality is good. Regular water changes are the best way.