Dying Coral

Ok, Water tested at Aquatic Dreams.  My tests are aging, and I dont trust them.  Results as follows:

Alk - 6.8 dKh

Ca - 410 ppm

Mg - 1300

I also had them test for Nitrate (5 ppm), they voluntarily tested Nitrite (5 ppm) and Phospahte (.12ppm) as well.  Higher than I like, especially the Nitrite, but the big shocker was my salinity.  I have always used a hydrometer, wanting to buy a refractometer for years.  Well, I finally bought one tonight.  Salinity was at 1.028.  My hydrometer read it at 1.022, which I calibrated at the store when I bought it.  In other words, my hydrometer read 1.022 with 1.026 water when I bought it.  

So, lowering my salinity as I type this.  Luck has it, I didnt have any fresh RO ready to go, so waiting patiently to make enough to get it down to 1.025 or 1.026.  

I also have a purple firefish.  Always timid of course, but hadnt seen more than his head in weeks.  Well, last night he came out, and is not looking  good.  Very skinny along his spine, but a fat belly.  Seems lethargic, but is swimming upright.  Seems he senses food, but I dont think he can see it.  Hoping it is salinity related also, and that I can get him back to his old self.

Also doing a 20% water change due to the NO2 and NO3.

Thank you for everyones responses.

I feel like an idiot for saying this, but after reading Marks last post again, I realize the importance that he stressed on temperature.  Either my thermometer is wrong, or my tank is at 60 degrees.  The LFS sold me the wrong heater, and I didnt realize it until I got it home, and havent taken it back because it is rated for 53 gals (my tank and sump is about 60), so I figured at worst, it would have to be on a bit more.  But I have noticed the past few weeks that the heater is almost constantly on (at least every time I look at it), yet my water temp is low.  I cant beleive its 60, but I still think it is low.  All other corals are doing fine.  I will post a picture of the tank in a few minutes.

"Alk - 6.8 dKh" Here could be a major reason for the coral dieing back but that's not all. It's a combination of several things discussed here. Temperature is one aspect but see below for my other recommendations.

I would say that raising the Mg caused the Alk to be better utilized, causing it to drop too low.

"Also doing a 20% water change due to the NO2 and NO3." The N levels (Ammonia, Nitrite and Nitrate) in this tank are well below a point for concern. No need for water changes to correct that supposed problem, but the water change would be helpful in slightly raising Alk and lowering Salinity.

The PO4 is high at 0.12 ppm. It should be 0.02 or lower. This calls for either an increased growth of algae in the Refugium and some Phosphate removal media. Either Activated Alumina or Granulated Ferric Oxide (GFO). May we see a full tank pic and a pic of the sump/Refugium. Assuming there is a Refugium, how quickly does the algae mass double in size?

Actually a salinity of 1.028 is not far enough off to cause any concern. Yes, 1.022 - 1.026 is the best range but a gradual rise in salinity did not stress anything. A slightly quick drop in salinity which I would do in 2 or three RO water additions over the next 24 hours will never be acknowledge by the coral. A hydrometer is as accurate as we need to be with salinity. Periodic cleaning of a Hydrometer with vinegar is very important. Calibration is easy. Using a Refractometer is more fun.


After Temperature, which if it really is 60, I would raise slowly over two days, the next most important thing I can see is to get the Alkalinity up and that's simple. Do you have Baking Soda in the house? Mix as much Baking Soda as will dissolve in a cup of RO water. Slowly pour half of the cup right at the Return Pump intake. In 4-8 hours pour the remainder and after about 15-30 minutes test the Alkalinity and let us know what it reads.