Anyone ever had a tank that refused to cycle?

[Reefkeeper]

For the last few weeks I have had a 10 gallon set up and cycling. The first 2 weeks or so, it was simply a powerhead circulating the water as I was waiting on an order I had placed. As is my usual method, I went to fast cycle the tank by using a 50% mixture of water from my established tank/50% new water and then adding a fast cycle mixture of nitrifying bacteria/food for that bacteria. FYI, it also had a very small amount of live rock approximately 1-2 lb during this entire time as well as some macro algae. (For the curious, the initial plan was to have a permanently set up hold tank/QT. However, I have decided that I am going to transfer several animals to that tank on a permanent basis.)

I wasnt bothering to test it since as far as I was concerned the main cycling wouldnt start until the filtration was in place. When the heater and filter came in, I immediately added that to the set-up. When I tested the tank 2 days later, my Ammonia, pH, and Nitrate are all fine (0, 8.2, and 5ppm respectively) but my nitrite is .25. My immediate thought was, gee it didnt cycle at all with only the powerhead. I added some more quick cycle to help jump start the cycle with the filter and sat back to watch what I anticipated would be a normal cycling process.

Every 2 days, I checked the system only to see that nothing was changing. My pH remained 8.2, Nitrates hit 10ppm after the second dosing but returned to less than 5ppm, and Ammonia remained at 0. Unfortunately the Nitrites have remained at .25.

Before anyone asks about water changes...I have done a few of them trying to knock down the nitrite level. Mostly 25% changes but one that was closer to 40%. The water that is going in is a mixture of the other tank water (0 am, 0 nitri, 5 nitra) and new salt water. My reasoning with this was that the other tank has a bioload and thus, adding some of this water would help with the cycle.

So at this point I am almost 3 weeks after the tank was initially set up, about a week with the filter. I have sucessfully cycled my other tanks within 1 week using the cycling additives I used in this tank. Thus, looking at it from either the 3 wks or 1 wk period, I should have seen some change in the nitrite level. (the change in the nitrate level seem to indicate that there is at least something going on)

Anyone have any idea why my nitrites seem stuck at .25? I have been waiting until I get the Nitrites gone before tranfering a few damsels into it to give it a growing bio load.

This is annoying the hell out of me as I need to transfer some Xenia and GSP into the 10 gallon. Between the crazy peppermints and some chemical competition, I want to give these guys a chance to recouperate without interference. (The xenia is in an intank fuge the gsp in a protective cup, but moving them will be better)

Ideas?

I dont think the macro or the water is at issue.

[colindoug3]

the gsp will make it without the tank being cycled. which type of xenia? red sea xenia i think is iffy, but im pretty sure xenia elongata can make it.

[bgoode]

Has the nitrite kit ever read 0? It could be a bad test kit. Try testing the water with a different kit, or taking it to AW and have them test it.

[suver569]

Yea, first thought was a bad test kit. Check for foreign object also. I had a pencil that almost wiped my tank out. It's a stretch, but look around.

[MrKrispy]

so do you still only have 1-2 lbs of live rock in there? If so that might be the problem.

[BrookR1]

A cycle could take up to 6 weeks. It almost sounds as if there wasn't enough ammonia (with only 1-2 lbs of LR) to really kick the cycle into high gear and get it going.

There are a few ways to approach this:

1) just wait it out for a few more weeks

2) add a small daily dose of ammonia (1 ml) to build up your biological filtration

3) add your damsel...they are tough fish and nitrites (compared to ammonia) aren't THAT toxic to fish. They don't have to be zero for your fish to do well. (ssshhhhh....pk-sd...before you jump in....read this http://reefkeeping.com/issues/2005-06/rhf/index.htm )

[chevell]

Not that it will make your nitrite problem go away but this article may put things in perspective.http://reefkeeping.com/issues/2005-06/rhf/index.htm

[suver569]

from that article, it sounds to me like macro algae in a cycling tank, will eat up amonia before it can be processed. Just food for thought.

[Reefkeeper]

For ease of explanation I said that I had the macro in there from the start, but the reality is that I added it after a week with the powerhead. Additionally, I was removing macro at a rate much higher than it grows as my Naso loves to eat the stuff so I seed my other tank with it.

As for the amount of LR, if I was only cycling the tank with the rock, then yes that would explain it. However, I was using a quick cycle nitrofying bacteria agent that I have used previously. Thus, the bacteria were in place and fed.

[swissfish]

My tank never cycled. I used cured LR from my old tank and scrips water. I checked every day but no signs of a cycle were indicated. I stoped testing after 3 weeks and havent tested the water since (6 Month later).

Ohh all the fish and corals are doing fine. I only lost a sandsifter goby but i think because he diden't have enough food.

[MrKrispy]

Originally posted by Reefkeeper

As for the amount of LR, if I was only cycling the tank with the rock, then yes that would explain it. However, I was using a quick cycle nitrofying bacteria agent that I have used previously. Thus, the bacteria were in place and fed.

how old is the bacteria stock? Was the same bottle used before? What is the "food" you gave them?

Do you have a substrate in your tank for bacteria? i..e sponge, biowheel, floss, etc...?

Because based on your amont of live rock, if you don't have a substrate for enough bacteria you might be removing what little you have in the water column with water changes. This would apply to the high nitrates as well, because they are much slower growing than the bacteria that break down nitrites. then again maybe it is just your test kit :)

[Reefkeeper]

The test kit is fine, I use the same kit for all my tanks and get different readings on every other tank. (0 nitrites in my other tanks, although while cycling they were higher)

Bacteria stock and food (Nitromax Marine - exp 12/7) is only 2 months old, always in the fridge and still alive and well.

Its a bare bottom tank as any QT/hold tank should be. With any tank where there may be a chance of using medicines, you dont want to have substrate or live rock. The small amount of LR that I put in there was mostly to provide areas to hide/place to put sessile inverts. The reason for the macro is two fold. I need to have some algae growth for any browsers that I want to separate/QT. Secondly, it allows me to prevent the macro from getting out fo control in my main tank. All of the patches I put in my main tank are eaten in a matter of days.

[socalkris29]

I had a similar problem cycling a 20. I think it might have been because the ammonia never really spiked -- and maybe this is the same problem with your tank... jmho. I also had ~50% "old tank" water with new asw and a protein skimmer, but no biological filter. The key is you want to cycle the "filter" (live rock, dsb, etc.), not the water.

After I added ~15 lbs. of live rock, it cycled right up -- took about 3 weeks.

:D
K

[Dakota]

I'm having a unique problem with my new setup. . . added the LR on Tuesday. It had been setup with 5 lbs of cured LR for about 2 weeks before adding another 50 lbs. I ran some tests today to see how it was doing.... 0 across the board, and a pH of 8.3. . . I knew the new LR was fairly fresh, but I would have expected some spike by now. . . I'll test again next week to see.

[Reefkeeper]

Finally...the Nitrites went to 0! I have no idea why it got stuck at .25 for so long but several days (and tests) later, its gone.

The day before it finally disappeared, the Nitrates went up a tad (10ppm) but then dropped to 5ppm, no nitrite, no ammonia, 8.2 pH.

I noticed there were tons of pods in this tank as well as a damn glass anenome (aptasia) which must have come in with some more algae from another tank. (It wasnt around at all before the algae even with the rock)

Now its a matter of "fishing".