SG question

[grussell]

Hi,

I just started cycling my tank. I have only marco rock and a couple of small pieces of seed rock(which have nothing on them besides bacteria). My SG is 1.024, and varies between 1.024 and 1.023. Temp 80.2. From what I am reading on these forums I want my SG around 1.026. Is this really a necessity? I use Instant Ocean. If I need to increase it am I still at the point where I can just add salt directly to the tank(Aside from the bacteria, there is NOTHING else living in the tank at the moment?) or would that kill the bacteria? I know you can't add salt directly once you have critters in there.

grussell.........

[snorvich]

For corals especially it is best to be about 1.025/1.026 and even for fish it is easier to maintain your target chemistry numbers at that specific gravity. But in the short term, with only live rocks, you are doing fine.

[disc1]

No harm in letting the SG stay a little low during the cycle. Save yourself on the salt. When you get close to stocking corals, start topping off your evaporation with saltwater instead of freshwater for a few days until the salinity comes up to where you want it.

[Palting]

You should be fine for cycling, and also fine in the future if all you want to keep is fish. Once cycled and you want to have coral, then raise it to 1.025-1.026.

NEVER, NEVER add salt directly to a tank with anything live in it, even if it's just live rock. Easy enough to siphon out some tank water to a bucket, dissolve additional salt and mix well, then slowly return in an area of strong flow. This is what I do when I raise my salinity back up from hypo in my QT. Or, you can do what David suggests: top off with salt water until the salinity goes up to where you want it.