Introducing new corals to ULNS

DannyB · Oct 22, 2015

So if I understand correctly, lowering PO4 and NO3 too quickly can result in a bad reaction from some corals, Sometimes resulting in RTN or STN . I believe this happened to my Hawkins Echinata when I switched to ZEOvit system.

My question, is there any special way to introduce new corals into a ULNS, to prevent possible problems?

Randy Holmes-Farley · Oct 22, 2015

Do you know it is coming from a higher nutrient system?

Tahoe61 · Oct 22, 2015

If you're going to run a ULNS you should probably not run the alk over 7.5.

ReeferCub · Oct 22, 2015

Very interested in the answers. Because, few weeks from now, i am going to transfer my corals to a ulns too.

DannyB · Oct 22, 2015

Randy Holmes-Farley said:
Do you know it is coming from a higher nutrient system?

I don't know this for sure but I am sure not all vendors will have ULNS. Is there a range which would be more of an issue?

Tahoe61 said:
If you're going to run a ULNS you should probably not run the alk over 7.5.

I don't keep my alk high but I don't keep it this low either. Is Alkalinity the real issue behind reducing nutrients too fast?

Tahoe61 · Oct 22, 2015

I notice decreased polyp extension, and in a rare case burnt tips if I try to run an Alk above 8 when I run an undetectable N/P. A coral not used to that change might stress.

When my system runs ULNS I am extremely reluctant to push the alk higher.

Randy Holmes-Farley · Oct 23, 2015

DannyB said:
I don't keep my alk high but I don't keep it this low either. Is Alkalinity the real issue behind reducing nutrients too fast?

I do not know if it is an issue for reducing nutrients too fast, but it appears to be a issue for ULNS in general. One theory is that higher alk allows the skeleton to grow faster than the tissue can keep up, resulting in very thin tissue at the growing tips of some SPS corals which is easily damaged, perhaps by light damage.

So I agree that if you intend to keep ULNS, I'd stick to alk not much above 7-8 dKH.

As to the transition itself, I've not actually heard of anyone actually trying to match nitrate and phosphate levels, but all sorts of things (usually undesirable) happen during coral transfers,a nd I'm just not sure if nutrient levels are a factor or not. Certainly, changes int eh otehr direction can lead to browning of corals as zoox levels expand in corals.

Randy Holmes-Farley · Oct 23, 2015

FWIW, I'm still not convinced that there's clear evidence that lowering nutrients "too fast" is ever an issue.

It may be, but clouding the issue is the inability of most folks to accurately know how low they actually took them. So going too low, which I believe to be an issue in some cases, and perhaps especially so when alkalinity is on the high side, may be the real problem, not the rate of nutrient level decline.