Tissue Loss Question, low salinity

Rickyrooz1

Acropora Nut
I usually keep my 120g's salinity at 1.026, KH at 7.0, Calcium at 420 and Magnesium at 1350. I went away for a week but before I left the salinity was at 1.030 so I took out some water and added fresh R/O water. When I came home the SG was at 1.022 and the KH was 7.7, Ca was 370 and Mg was 1050! My Purple Tri-Color turned brown and two of my green acro's started to lose tissue. Could this have been caused by bad alkalinity values or a low levels of Ca and Mg or because the salinity dropped?
 

bertoni

Premium Member
A fast SG drop could cause a lot of coral damage, in my opinion. Did you mean 7.7 dKH for the second reading? That's close enough to 7 dKH that I don't think it'd be an issue.
 

Rickyrooz1

Acropora Nut
Found out why my Alkalinity went up to from 8.0 to 10.9 dKH. I opened up a new container of Red Sea Coral Pro and performed a 25% water change on 1/2/08, I left for vacation on 1/7/08. I tested the new saltwater I made (aged for 3 days) and the Alkalinity read 10.9 dKH! I'm really mad that Red Sea made a bad batch of salt. The container I bought before this one was reading 8.0 dKH.
 

Rickyrooz1

Acropora Nut
I just tested the Ca of the new water and it was at 452. The Ca is good but the Alk. is too high. I'm really upset with everything that is happening to my tank. I turned on the lights today to see how things were doing and my Montipora Undata has white marks (tissue loss) and my Orange Cap has a white rim of tissue loss. Also my Purple Lokani turned brown. Basically all my acro's look really bad or are dying except for my ORA Green Birdsnest and ORA Blue Tortuosa. The Green Hammer, Green Frogspawn and Fox corals are completely closed up. My GSP is completely closed and my Xenia looks like it's about to crumble. Do I do a water change with new Red Sea salt, go back to Tropic Marin and perform a water change with that mix, or move the corals to a new tank with new saltwater that is lower in Ca, Mg and Alk. I had the lights off for all of yesterday and most of today hoping it would relieve them of the stress. They're not acclimating to the new conditions, Ca - 494 (possibly over 500), Mg - 1500, Alk. - 10.2 dKH.
 

Icefire

Seasoned reefer
sorry but a 25% WC with 10.2dkh water would only raise your tank alk by 0.5, nothing to worry about.

Also, alk can go up to 12 with no problem.
 

bertoni

Premium Member
Okay, that's good. I suspect the problem is damage from the sudden salinity shift. Let's hope for the best.
 

Rickyrooz1

Acropora Nut
Should I go back to using Tropic Marin Pro Reef salt mix since I was seeing good results with that? I only switched to Red Sea Pro because it was $39.99 a bucket instead of $69.99.
 

bertoni

Premium Member
I don't know which route would be more successful at this point. I suspect either salt will be fine, although there's some chance of a bad batch of salt being a problem. Usually, that's detectable with the water parameters, though.
 
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