Specific Gravityv - HELP!!!!

ander88

ander88

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Apr 29, 2009
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Dumfries, Scotland
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HELP!!!!

Hey guys

Got a big big problem with SG, it has crept up all of a sudden! My fault - my refractometer was out of calibration.

Now my SG is way up at 1.027 and should be 1.024

LFS told me today to do a 40% water change all at once, as my nitrate is up at 50ppm also my fault.

Only thing was he couldnt tell me what to mix my salt at to bring it down to 1.024. Do i mix it at 1.024 and put it in, or should I mix it lower?

Any help much appreciated!! Thanks in advance!
 
Calm down a bit. A specific gravity of 1.027 is not, by any means, outside of the appropriate range. @ 77 degrees F, natural seawater has a specific gravity of 1.0264, so your range should be fine. If anything, 1.024 is actually a bit low. When you say your refractometer is/was uncalibrated, what were you using to calibrate it? If you used RO/DI water, you've potentially opened up room for more error. It is better to get a standard that is based on natural seawater. I prefer Pinpoint Salinity calibration solution. As far as your current salinity, it will be fine. Just don't let it get too much higher. I'd say between 1.026-1.027 is the ideal for most of the animals we get, minus any that are used to or prefer higher or lower concentrations.

That aside, are you also using any 2 part calcium and alkalinity supplements? Those will actually slowly raise your salinity. YOu will occasionally have to remove some water and add freshwater in place to account for the rise in salinity.
 
Hi Amphiprion.

OK I'll not worry as much about that then, just taking what LFS told me, was just getting worried about everything because Ive lost two fish in two days and my corals are detiriorating.

I think ive got it calibrated now, it matches the reading that the LFS made with there test. My Temp is at 77 79 degrees F

I dont use any supplements, only what is already in the salt i use. Red Sea Coral Pro. PH is also slightly low, its at 7.8, shoundt it be 8?

Sorry if im coming across as a big novice.

Thanks again
 
Not a problem at all--the point is to learn. There's no reason to apologize for being new. pH is a bit low, but still within the appropriate range (7.8-8.4 is the acceptable range). Again, instead of having your refractometer match your LFS, I highly recommend that you purchase a known standard--you don't know how their refractometer was actually "calibrated." Again, the Pinpoint calibration solution works well for many people. Can you post all other relevant parameters, like calcium, alkalinity, phosphate, etc. Also, have you tested the quality of the water you are using? Are you using RO/DI water? What TDS is it reading (if you buy water from the LFS, some aren't truthful about their TDS readings). Then again, the animals may be severely stressed from the start. There are many potential factors that can cause what you are seeing. An improperly calibrated refractometer may be part of that and I have my doubts as to whether or not your LFS's refractometer is accurate, as well, unless they are using a known standard (and not plain RO/DI water).
 
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Ok ill get onto that calibration solution as we speak.

Im using RO water for my top up and changes, and when I run out I use pre-mixed from LFS, but that is once in a blue moon. And I have no way of checking TDS.

Water Paras I have tests for as follows:

PH = 8.0
Alkalinity = Norm 1.7 - 2.8 Mili Equivalent Per Litre Range
Nitrite = 0.1 ppm
Calcium = 450 ppm
SG = 1.027
Nitrate = 50 ppm
Ammonia = 0.25 ppm
Temp = 77 79 deg F
All kits are Red Sea apart from Nirate which is a nutrafin kit
 
Go ahead and get a TDS meter. They aren't very expensive and are one of the most useful things to have in your, well, "arsenal."

The alkalinity is extremely low. 2.5 meq/L is the bare minimum and 1.7 is unacceptable for most corals (and is far from normal). Use some plain baking soda (not powder!) and this site to get things back to acceptable levels. The salt mix you use also has minimal alkalinity, so I would suggest that you boost it before using it. Just use the same calculator in the above link and the volume you mixed for a water change to get how much you'll need. 2.5-4.0 is a more acceptable range, and I prefer mine to be around 3.0 or a bit higher.

I also hope those ammonia and nitrite readings are false. If not, that would indicate there is either something that died or the tank hasn't finished the cycle. Nitrite isn't really as much of a problem, but the ammonia definitely is. I would do a water change, but only when everything is calibrated properly. You may also want to consult a second set of tests. Red Sea isn't noted for being terribly accurate. I suggest Salifert for all kits except alkalinity. The only alkalinity tests I like and seem to be more accurate are Elos and LaMotte.
 
Ok, was just going by the test card in the red sea kit for alkalinity.

I lost my yellow head jaw fish yesterday, found skeleton so could be contributing and lost a banner fish 2 days previous but was still all there.

The fish that are still there are gettin white spots everywhere, im afraid I might loose them before I get sorted.
 
I wasn't saying that you necessarily thought it was normal. That was directed at Red Sea and their idea of "normal" and to also alert you that it was not. More questions. How long has the tank been set up and how long have the fish been in there. Sounds like your ammonia results may not have been too far off. The resulting stress is allowing marine ich to opportunistically spread. At this point, regardless of the salinity, you need to do a water change (a shift of 1.027-1.024 isn't much. You could add some freshwater now to lower it a bit before you use your LFS's water and ease some potential shock). How many other fish do you have in the tank and how big is it? Something is definitely going wrong and we need to find out where.
 
The tank has been setup since april this year, left it a week then added cured LR, left it 3 weeks then started to stock.

At the moment 2 common clowns, 1 small regal tang and 1 firefish. Various snails and hermits. 3 leather, 1 anchor, discoma mushrooms, 2 sponges, 2 sea squirt.

Tank is 125 litre (roughly 30gallon)
 
Water change just done, only managed to change 12 Ltrs, all the mix I had made up, going to get more tomorrow from friends and lfs and compare.

New water paras as follows SG 1.024, PH 7.8, Alk 1.7-2.8 Range, Nitrite 0.05, Nitrate 0, Calcium 450, Ammonia 0

Will do full tank tests in morning before work (5am GMT) and post if possible, then more water changes after work (3pm GMT). Going for 25%. Think that would be OK?
 
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