Tissue Loss Question

[Rickyrooz]

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?

 

[chadfarmer]

i would say all of them

 

[J. Montgomery]

How are you measuring alkalinity, what test kit?

How are you measuring salinity, and have you calibrated it lately?

 

[twon8]

7 is on the low end of acceptable, i try to be closer to 8 than 7.

and yes, low alkalinity can cause tissue recession.

 

[Rickyrooz]

I use API and Salifert to double check the values.

 

[surfn]

i recently had the same problem in regards to drop in alk, calcium, and magnesium. still fighting the RTN on 2 colonies.

 

[Rickyrooz]

I added Calcium and Magnesium last night and tested this morning. My Salinity was 1.026, Ca was at 600 and my Magnesium was at 1500! I went to the LFS to double check the values in case my test kits were off and everything checked out. The corals still look bad so I'm hoping they just need to reacclimate to the rapid changes in salinity and will start recovering in a few days.

 

[Rickyrooz]

Do you recommend I leave everything the way it is or try to bring down the Ca and Mg with a 20% water change while keeping the SG at 1.026 which it is at now? What will help my corals and parameters get back on track?

 

[aquarius77]

I would let them come down on their own.

 

[J. Montgomery]

Water changes are always good, and those numbers seem way too high. Did the LFS check your salinity? Have you calibrated your refractometer or hydrometer with a standard (not RO/DI water)?

 

[Rickyrooz]

Yes, I calibrated it with PinPoint's solution and the Refractometer was reading 0.001 lower than normal. The LFS didn't test salinity, just pH, Ca, Phos, Ammonia, Nitrite, Nitrate.

 

[J. Montgomery]

OK, cool. The topic of refractometer calibrating had come up in our local forum lately and most of us were reading lower than expected.

 

[Rickyrooz]

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.