Water changes not lowering nitrites?

[NotGumbel]

I moved my biowheel filter from the old 20g tank to the new 45g one. However, I lost much of the beneficial bacteria when the filter died a few days later, and went into a small cycle.

The ammonia phase is over. However, I'm having trouble reducing the nitrites.

Shouldn't water changes reduce them? I can do a water change of any volume (5% to 60%) and the nitrite level will not reduce itself.

Following advice on another site (sorry, AC was down) I added salt to detoxify the nitrites (2.0 at that time), and stopped doing water changes.

After about 7 days, nitrites dipped from 2.0 to .25.

However, once I did a water change, they zoomed back upwards!

I could use some clarification - I don't want the fish to be in misery, or to keep setting myself back. :help:

FWIW nitrites test zero from the tap. Nitrates are +/- 20, and ammonia remains at zero.

Thanks in advance,
Bryant

 

[budrecki]

You are in a cycle. You need to continue the water changes, as much as 75% every day if needed, to keep those nitrites down under .25. It may take weeks for your bacteria to recover.

 

[NotGumbel]

Shouldn't I at least see a drop in nitrites after a water change, though?

 

[OrionGirl]

I depends. Hobbysist test kits have a max test level--if there is 5 ppm present, and the test only goes to 2 ppm, then even after a 50% water change you will still get a test result of 2 ppm, even though it's been diluted by half.

However--wince the nitrites fropeed, then increased ramatically, I'd be concerned about something else happening in the tank. Other parameters? KH, pH? Ammonia?

 

[loaches r cool]

I thought I read somewhere that you shouldnt do a 50% or more water change during cycling because you will suck out alot of the bactaria in the water cange and that will extend the cycling time out further? I dont have first hand knowledge though... my last three tanks really didnt need cycling when I started them.

 

[NotGumbel]

I depends. Hobbysist test kits have a max test level--if there is 5 ppm present, and the test only goes to 2 ppm, then even after a 50% water change you will still get a test result of 2 ppm, even though it's been diluted by half.

The max on my test is 5.0, and it's not gone that high. So in theory, when it's 2.0, and I do two 50% changes within a day's time, shouldn't I see at least a small reduction in nitrites? Particularly when I repeat the process 5 consecutive days?

However--wince the nitrites fropeed, then increased ramatically, I'd be concerned about something else happening in the tank. Other parameters? KH, pH? Ammonia?

Fropeed = dropped, I'm guessing? (darn keyboards)

Ammonia = 0
pH = 7.0
Phosphate = <0.5

These three readings have remained constant for the last three wks.

I don't have a GH/KH test; it was out of stock when I ordered it from Big Al's.

The only other events that happened was adding a few anacharis, and putting an intake tube extension on the Aquaclear power filter. Any filter maintenance involved rinsing media in tank water.

Thanks for your input, I appreciate it & hope I can get this under control for my guys.

 

[rrkss]

Test your tap water. My tapwater routinely tests positive for Nitrites. Sometimes they even go up to 1.0 which is the EPA max for Nitrites. As you can see doing waterchanges with my tapwater would not lower Nitrites but probably raise them.

 

[OrionGirl]

I thought I read somewhere that you shouldnt do a 50% or more water change during cycling because you will suck out alot of the bactaria in the water cange and that will extend the cycling time out further? I dont have first hand knowledge though... my last three tanks really didnt need cycling when I started them.

Just to nip this in the bud--this is false. The beneficial bacteria ARE NOT in the water column. Removing water will NOT harm the bacteria, and it will not starve them. As long as conditions are good for growth, bacteria will grow--10 times their needed food supply doesn't foster faster growth, and when dealing with ammonia, can hinder growth. Regular water changes, as with a mature tank, are actually very beneficial since they help maintain the water parameters, replacing buffers consumed by the biological processes.

In this case, with other factors stable, I'd agree that looking at the water source is a good step.

 

[NotGumbel]

In my initial post, I stated that I have been testing tap water for nitrites - they are always zero. Good suggestion otherwise though.

 

[Ms.Bubbles]

I'm wondering if adding the anacharis in the nitrite stage of the cycle might be interfering in the cycling process--perhaps using up all the needed nutrients and thereby starving the nitrifying bacteria that would normally be consuming the nitrites???

Another idea--are you using enough dechlorinator? If chlorine is present in the change water, it may be killing off the nitrifying bacteria whenever you do a water change...

PS. Please don't apologize for going to other fish sites--the more you learn the more you can share with us!