Gravity????

[SLAYCHILD]

Does any one keep there salt gravity at 1.026 witch is the natural saltwater from the ocean or at 1.022? Ive been keeping mine at 1.022 and ive read that it should be at 1.026. Can someone help me out, thanks

[hobogato]

i keep mine at 1.024 - 1.025. i think it depends on what you have in the tank. many people who keep SPS corals keep their salinity here or slightly higher. if you have softie corals and fish, the lower salinity is ok i think. when i ran a FOWLR tank, i kept it at 1.023 (what it mixed to using the directions on the bucket of the salt).

[GaryP]

For a reef tank 1.024-.026 is good. Not only is the sailinity higher, but so are things like calcium, alkalinity, and magnesium by running at a higher S.G.

[discuspro]

Are you using a refractometer? When looking at specific gravity you also want to look at temperature as well. From these two types of data you can find what salinity your tank is at, I believe natural salinity is around 35ppt.

[jap1]

I'm not trying to start a refractometer vs swingarm debate, but make sure you know where your salinity REALLY is. If you don't have a refractometer, and LFS would probably be happy to let you use theirs. I always thought my salinity was at 1.025 with my deep six hydrometer, but when I tested it on a refractometer at the LFS, it was 1.031! I never had any bad effects though. All my inverts did just fine, but I finally got my refractometer last week. Well worth the purchase.

[Reef69]

1.025 here.. Isnt lower salinity easier for fish to swallow??

[discuspro]

You know what is also a very accurate way to measure s.g. is a floating glass hydrometer in a glass/clear cylinder. It is not as fast as a refractometer but it can cost less, sometimes, and be super accurate as long as it has been calibrated. The only thing is you have to use a salinity conversion graph. You know what never mind, it is a bunch of work but it is how I do it at the lab.

[Reef69]

LOL..Ok, thanks!!

[GaryP]

Refractometers can have accuracy problems too. They aren't as much as a refractometer though. I still use a swing arm that I cealn with vinegar regularly and calibrate it against a borrowed refractometer every once in a while.

Discuspro is definitely right about the glass floating hydrometers. The problem is getting a conversion chart for them. The ones you get at the LFS are calibrated to 77 F. That's probably good enough for most people but I would still check them against a hydrometer to make sure they are in the same ball park. However, the better quality ones are available from beer brewing shops and they are calibrated to 60 F. There are several temperature conversion calculators online at brewing websites.