Algae Blooms, Wilting Xenia, Livestock Issues with Perfect Water

[ssungyo]

Hey guys,

I'm having a few issues with my tank and would really love your help! Thanks in advance!

I have a 12 gallon JBJ nanocube that I've had running with

- 20 lbs of live sand
- 10 lbs of live Rock
- Premixed RO/DI water from my LFS
- Aqua Euro Skimmer
- MaxiJet 900 with Hydor Flo (as Return pump and outlet)
- Activated Carbon and Bio Rings (filter media)

and the tank has been running for almost 2 months now. The initial cycle and algae bloom came and went and then there were small spikes along the way (all of which, I took care of with regular 10-25% water changes weekly).

Since, I've introduced progressively the following livestock:

- 1x lawnmower blenny (flourishing, super active and very healthy)
- 1x small florida ricordea (irritated)
- 5x small hermit crabs (half of them lack of activity)
- 5x margarita snail (half of them lack of activity)
- 1x fire shrimp (DEAD)
- 1x cleaner shrimp (DEAD)
- 1x small GSP colony (DEAD)
- 2x blue xenia (1st one DEAD, 2nd one shriveling up now and not healthy)
- 1x mandarin dragonett (shy during the day but active at night)
- 1x frag of some baby zoas (awesome at first, most polyps are closed up now)

So i'm confused. Everything starts off doing really well in my tank, and then when i do water changes, it seems to irritate my livestock and algae seems to reappear. I have been going back and forth from my LFS to get my water tested which always shows perfect water quality on every parameter. from salinity, to ammonia/nitrites/nitrates, to alkalinity temperature and every other parameter... my water quality is pristine.... however, everything but my lawnmower blenny seems to be failing.

I am perplexed, the guys at my LFS (who I trust) are confused! I'm afraid of buying more livestock and/or coral and would like some advice. What do you all think it could be?

[JJ650]

I had a related issue as well. As far as I could tell, my parameters were spot on. I had my Xenia die off (around 60%+ loss) and I started seeing Macro algae spring up all over the place.
I then started having Acropora STN (slow tissue necrosis). All other livestock including fish, inverts and corals were fine.
I was getting wild Alk swings from one day to the next. In fact I still have some funky alk swings. Check all media, and post water parameters.

You mentioned your system being 2 months old. Are you sure it was fully cycled?

[ssungyo]

thanks for the input! I have been following along and monitoring my water parameters throughout and am pretty sure the tank is cycled (for the most part) as I've ridden through, with careful observation, the nitrogen cycle and it's spikes. book says, it is cycled but I could be wrong. All i know for sure is that the water parameters have been pristine all throughout the 2nd month with no fluctuations even when introducing new livestock. I check the parameters in the morning when i wake up and once before i go to bed.

[sidewinder2180]

Can you post your most current water test results?

[JWClark]

May be cycled but not ready to handle increased bio-load. Adding critters too fast can cause a secondary cycle as more waste is produced than the bacteria population can handle. Go slow and be patient. It is going to take 6-12 months for the system to mature. With such a small volume I would not change more than a gallon a week. More than that and you are more likely to have water quality parameter swings. What salt are you using? Is the saltwater itself pre-mixed at the LFS? Could be that changes in salt could be an issue?

[JWClark]

Also, is the tank new or used?

[bertoni]

It's only a 12g system, with 10g of live rock. That fish load might be too much for the filtration.

[nmotz]

Hmm.. my thoughts are that you have excess nitrates. The reason I think this is because your inverts and coral are really struggling while your fish have at least survived. Invertebrates are usually more senstive to nitrates than fish. Bio rings can start leaching nitrates back into the tank. But I feel like you would have seen this on your water tests. What are you using to test with? Seems like an excess nutrient problem to me. Water quality is a struggle in such a small tank. The other thing may just be a general lack of stability. You have to remember that lots of WCs will alter all your parameters and that may be impacting your tank too.

[oseymour]

that's a huge bioload for a small tank, and a tank that's 2 months old. Also what are you using to test? Don't use the strips or API tests, they are very innacurate.