stn issues related to carbon dosing?


New member
Hi guys

Some info on has been through some issues a month ago with temperature fluctuations etc due to broken fan failing to keep temperature down, where then after few days of heat a cold day came and new fan stayed on dropping temp down while at work..then two weeks later have electricity supply cut for a day due to maintenance yada yada yada

I am having issues with stn from bases of certain acropora..mostly happening with Milliporas and certain acroporas.tricolour secale, birdsnest and montis are fine..can the carbon dosing be causing it as the temp has been stable at 26degrees for last three weeks and all affected corals from temp incident died and were removed.

info on tank...4 foot tank with 85w intellisun led units and 54w t5s

Salinity: 35 ppm
Calcium 400
Kh: 7
PH: 8
Magnesium: 1400
Nitrate: 15 (its high as tank has a lot of fish which I plan on removing once I get a chance)
Phosphate: 0.5
Potassium : 400

doing diy through grotec doser so parameters are pretty stable as I have been monitoring every few days for last three weeks.

can the carbon dosing be causing the STN? I have a little biocubes in sump which are being depleted so I supplemented with VSV dosing at 0.2ml per 20gallons last two week...then it seems the stn got worse

any idea whether the vsv is causing it and what I can do to stop the stn..I do like the vsv dosing as its pretty flexible in terms of maintaining nutrient levels once I reach desired nutrient levels


New member
Are those your "regular" parameters, or did you check all those recently. I only bring it up because I had a similar issue, where we had a cold spell and my temps were fluctuating wildly. To make a long story short, corals stopped growing and I kept dosing so my Alk skyrocketed, then causing some burnt tips and some minor base recession. I was also carbon dosing so the high alk does not mix well with that. Not saying this is the case for you, but I had a similar situation so thought I'd share.

That said, all those sudden changes are enough to case recession all on their own. My advice is don't try to correct anything. Just keep things stable and where you know they should be. Sometimes actively "fixing" the problem makes it worse, LOL! GL!


STN from the base usually means low alkalinity. what do you test it with? you can raise it to around 8 since you are not exactly running ULN.


Just Reefin'
I'm having some STN from the base and my alk is sitting around 8.6. I had a swing recently into the low 7's, and the recession started some time after i slowly brought up my parameters back to normal..

It's certainly frustrating and after losing about 50% of my red planet, the recession stopped, and the living part of the coral are now growing and encrusting back onto a rock.

Hope you figure it out and want to tag along.


New member
Those have been my parameters for last two months of testing. .i keep a log of test results

I doubt i have pests. ..dusky wrasse has cleared out any issues i had before. .best addition i made to live stock list i reckon

Using a red sea test kit..I have started increasing kh slowly over last few days and will bump it up to 8 or 9. Thinking about it now...maybe the kit is not that accurate and over reading best thing is to up dosing very slowly over few days to increase kh and see

Stupid question. ..what nutrient levels would one consider uln?


New member
I have had stn as I have increased dose of vinegar and vodka. Never used sugar. But when I get to. 08ml per gallon of vodka I can't push it anymore without stn. See new Totm I just wrote about this.also on way up plenty of people report stn. High lights, gfo and carbon dosing along with alk swings. Forget it.!! Stability is key.


New member
my tank has been pretty stable since my issues...I wonder if I should bump up kh slowly over few days to 8-8,5 and see how sps do..


Just Reefin'
my tank has been pretty stable since my issues...I wonder if I should bump up kh slowly over few days to 8-8,5 and see how sps do..

I slowly bumped mine up to 8.6 and I believe it has moderated...


Lost as usual
Do you use vinegar and vodka? When you dose vinegar, did you observe your PH drop significantly in a matter of minutes? I found when I did that, my PH dropped 0.4 from 8.0 to 7.6. Now I only dose with vodka everyday without using vinegar. I just want stability for every parameter.