sps stn from the base

[loster]

i find it hard to understand why some of my sps stn from the base. i have no problem with the aquaculture. but those are not, they always show the sign of stn and than stop for a while and than start again

water parameter:

ca = 380ppm (stay at that level for 2-3 weeks) now i am slowing raising it up to 400

dkh = 9.3 (stay around 9-10 for last 2-3 weeks)

mg = 1250ppm

sg = 34pp

ph = 8.0 (night), 8.1 (day)

temp = 27 - 27.5

[AlfaRomeo]

What happened before 2 weeks ago? Did the KH crash? Sumtimes kh crashes a few weeks ago will having implications a few weeks later esp if it is an extended crash. IME..

[loster]

my dkh stays around dkh-10 two & three weeks ago. it was around dkh-9 four weeks ago

i understand that dkh crash and it will takes around 2 weeks to see the effect on sps. the thing is i really don't understand why it happens when my dkh stays within constant 9-10 dkh

[AlfaRomeo]

How about water flow around the base of the SPSes which STNed?

[loster]

i have 2xtunze 6060 and 2x seio 820 + ehiem 1262 as return + eheim 1262 from chiller to direct return.

those base that stn has a good flow also

[ciaolong]

mine also one of my colony has just started to get STN at the back dont know why all para are fine .... really weird :S

[madmac]

This was asked in RC to determine the problem... if you break the base where the STN happens.. do you see a green tint in the crack portion?

If you do, then the SPS is ###### up phosphates from your LR. The explanation given was that SPS are rocks too and that can take in PO4, except it surrounded by living tissue. So if the above happens green tint... the problem it you have a serious PO4 problem.

Loster, I had cyano all over the rocks, but none of the SPS...so far... shows STN... maybe its time you cook your rocks to rid the nutrients.

A temporary solution is when you mount the SPS, glue the base first then epoxy them to the rock.

[loster]

This was asked in RC to determine the problem... if you break the base where the STN happens.. do you see a green tint in the crack portion?

If you do, then the SPS is ###### up phosphates from your LR. The explanation given was that SPS are rocks too and that can take in PO4, except it surrounded by living tissue. So if the above happens green tint... the problem it you have a serious PO4 problem.

Loster, I had cyano all over the rocks, but none of the SPS...so far... shows STN... maybe its time you cook your rocks to rid the nutrients.

A temporary solution is when you mount the SPS, glue the base first then epoxy them to the rock.

just camee back... hmmm... i am going to check it out tmr

[dominik]

Pai seh, what is STN?

[Aged Salt]

Hi all, if all parameters are inline & stable, larger wild colonies in general are tougher to keep healthy compared to smaller aqua-cultured pieces because of inadequate light & flow to the larger colony's base. Many times part of the base gets shaded by placement in our reefs, which over time renders STN. Same with current flow. As the coral grows so must the flow. IME, KH swings of 1 dKH are too much for Acroporas to tolerate. Loster, if I may make a recommendation, keep the KH within a tolerance of 0.5dKH. Your Ca level to your KH level is too low for long-term health of some SPS. With running a KH of 9 or 10, the Ca should be around 425-450. One can run a Ca of 380 if your KH is in the 6-8 dKH range. Mg levels should always be >1250. I have always had better long-term success with running my parameters at NSW. Bob