Help my Nitrite reading

[AndyAps.com]

I am trying to get my 3foot tank established for 11 zebras. it used to hold a breeding pair of oscars. i runs 1 internal and an external ehiem filter.
My problem is i took the oscars out and put them in a seperate tank, i cleaned the tank and removed the old sand and did a 50% water change for new de chlorinated water. i then added 20 zebra danio's to keep the filters cycling. the nitrite reading along with nitrate and ammonia used to be 0 with the oscars. i put in the danios and did the water change and my nitrite has rose to 25ppm. i have added cycle and done a 20% water change however i cant get it below 25ppm. its been at this level now for 4 days?????? i cant figure it out. if the filters could cope with 2 heavy feeding oscars whats the problem now???

[Adam]

Hi Andy,

I think that your clean up may have been a bit too thorough. There's probably not too much you can do other than to carry on adding the cycle, the readings will eventually settle down. Did your clean up include the filters as well? If so this could be the reason as you may have inadvertently killed off a lot of your filter bacteria.

[McEve]

I think what you describe is normal. You have done a heavy waterchange, and removed all the sand. That's a lot of bacteria gone.

Give it a week and you'll probably see that it's going to be back to normal.

You will get input from the others here as well I'm usre, as there are several people here who knows the cycling mechanisms and how it works a lot better than me.

[AndyAps.com]

No i specifically left the filters so they kept the biological maximum.
i also added another external filter an ehiem 2126 to the equation to try and settle it down but it has made it worse. i really cannot figure this out. unless the sand i removed housed all the bacteria?????

[McEve]

The sand would have housed a great deal of the bacteria, but not all of course. Now you have a new filter that needs to establish a bacteriacolony as well.

I still think what you describe is normal, give it a week or two and it will settle down I'm sure....

[Adam]

Andy, as McEve says your substrate would have also housed a large colony of nitryfying bacteria. Now that you have removed it your filters are having to adjust to the additional load hence the increased nitrite reading. You are pretty much going to have to let things run their course, it should settle down in a couple of weeks. I would try to avoid too many water changes though as you will only prolong the whole process. The higher the readings are allowed to become the quicker your tank will cycle. I would only do a water change if the nitrite level gets dangerously high as you may lose the Danios otherwise.

[Dr. P]

If you can, can you bag up some of the substrate from an established tank and add it to the (soon to be) zebra tank? This will help the bacteria colonise, especially with the new eheim.

You can use any type of filter bags....or even a NEW, unused pair of tights/panyhoses.

[Des]

Hi AndyAps.com.

You say that the nitrate level with your Oscars was 0. Are you sure? It is very rare for Nitrate to be zero. ( especially with Oscars)
Anyway, with your current problem ,it may be that your zebras are eating more, and therefore creating more waste than your 2 oscars ( very unlikely though !!!). Like the others have said , it should settle down in time.
However you could try, adding Cycle to a drained sponge from your external, instead of adding to the water, then replace sponge and restart filter.
You could also try using a piece of Polyfilter.

Regards,
Des.

[AndyAps.com]

yeah i have already drained the filters and added cycle directly to the sponges and sintered glass media. hoping this will work, the level is already dropping but i am picking the 11 Zebra plecs up 2mora so hoping iot will be 0 for morning.

[Tom2600]

I'm not sure I have ever personally witnessed a nitrate reading of zero, although I have heard this myth reported a few times. If your filter is mature and you are feeding and have fish and no substantial denitrification process I personally do not think a 0 nitrate reading is possible. However, 25ppm is nothing serious providing you keep the water changes regular.

I am sure your new zebras will enjoy their new home.

Regards

Tom

[Shell231]

are you getting the fish from a shop or a average joe on the street?

[Des]

AndyAps,
Was your Nitrite level 25 ppm or did you mean Nitrate.
If it is Nitrate, then , nothing to worry about.
If it is Nitrite, it is dangerous.
Des.

[AndyAps.com]

hi everyone,
well done, as everyone picked up i made a mistake entering the nitrite/nitrate readings. my nitirite is 0.25ppm and my nitrate is 10ppm (not 0) it used to be 30 with the oscars.(due to lots of water changes, those guys are very messy)
i didnt end up picking the zebras up cos the readings hadnt dropped enough. hopefully tho i will pick them up this week. they are from a shop shell.