Wondering if I need to do a water change

[ucdcrew]

I'm 5-6 weeks into my fishless cycle. The ammonia has gone down to 0, the nitrite is showing >5ppm on an API test, and the nitrate is bright red (160 ppm). They've been that way for over two weeks. If i have that much nitrate, I've got to have some nitrite-nitrate converting bacteria right? Is it possible that it is so saturated with nitrate that it is inhibiting the conversion? In other words, should I do a water change?

[lazydaze73]

No. Just wait. It'll magically come down one day

[toothybugs]

Over 160 is pretty high. I don't see any harm in doing a change, but I would keep it to no more than 40%.

Be sure your nitrite is measurable afterward so you can watch it disappear.

[Azedenkae]

If your nitrates is that high, yes, do a water change. 100% if you like.

[ZeeSparrow]

over 160 is pretty high. I don't see any harm in doing a change, but i would keep it to no more than 40%.

Be sure your nitrite is measurable afterward so you can watch it disappear.


+1

[ucdcrew]

I wonder how it got that high. I must have misdosed my ammonia.

[Azedenkae]

It also had 5-6 weeks to accumulate that much. What sort of biological filtration do you have going?

[ucdcrew]

I put 1 piece of live rock in with 100 lbs of dry rock

[Azedenkae]

I put 1 piece of live rock in with 100 lbs of dry rock

How much ammonia are you dosing? Are you using any sort of food like seafood or fish food or whatever? Or just ammonia-dosing?

[ucdcrew]

I used Dr. Tim's ammonium chloride. I was supposed to add enough to get 2ppm ammonia, but i didn't let it float around enough before testing and adding more the first time. I haven't put any in since then. It went up to around 5 ppm

[Azedenkae]

I used Dr. Tim's ammonium chloride. I was supposed to add enough to get 2ppm ammonia, but i didn't let it float around enough before testing and adding more the first time. I haven't put any in since then. It went up to around 5 ppm

Do a large water change today - as much as possible, add in enough to get it to 2ppm, and then measure again after 24 hours and see what the level is then.

[ucdcrew]

Update: The nitrites are still there. I did a water cha nge on the 19th of March. Nitrites down to 0.5. I wanted to make sure I could still see them. I waited. Nitrite got higher. Nitrates seem to be slowly increasing (but not 160 - more like 10 increasing to 20). All reading as of tonight:
Ammonia - 0
Nitrite - 1-2
Nitrate - 20
kH - 8
pH - 8.2
Temp: 80
Using RO/DI auto top off about 5 gallons week.
Oddly enough, I used some media from the sump to jump start a cycle in my (inhabited x 1) QT tank, which has now cycled. Go figure.
RO tests 0,0,0 and 0 TDS. QT tank 0,0,5.

Tank Stats:
100g acrylic
~120 lb dry base rock
10 lb live rock
60 lb dry sand
I'm running everything but my skimmer. Tank is running about 1000 gph through sump, and I took 1 of the powerheads out, but the other is 1450 gph.

Idea 1: try to get another piece of live rock somewhere.
Idea P: bacteria in a bottle??
Idea VI: I have a bag of caribsea 'live sand' that I could put in the refugium section of my sump. I bought it because I ran out of other sand.
Idea seven: turn the aquarium into one of those ring toss toys from the early 90s.