[DougJP]

I think I may have filled my tank too much. I don't even have the sand or live rock in there yet. If I take out enough water will it screw everything up?

[glampka]

You can take the water out without screwing things up since you don't have anything in there.

[carmanimports]

ya just save the water in a jug for later use ucz the evaporation u will use it in a week or 2

[jimw369]

If the water you are removing from your tank has already been mixed with salt you will not want to use it for "top off water". Water that evaporates is replaced with water with no salt mixed in it yet. If you use saltwater to replace evaporated water your salinity or SG will rise and could go dangerously high.

[carmanimports]

explain to how water of the same salinty as ur tank premixed with salt would make it rise higher because i use a homemade auto refill out of a 5 gal jug and i premix and have not had that happen to me

[rlcline76]

It's like this: When your water evaporates does it take the salt with it? No, just the water. Hence, pure and simple RO/DI sans salt is the way you want to go. Now, if you are performing a water change, you are removing both the water and the salt, SO that is when you use saltwater. Think about it.

[jimw369]

I can not explain that for you.

Do you use a refractometer for measureing SG? Hydrometers can be very inaccurate sometimes.

Originally Posted by carmanimports

explain to how water of the same salinty as ur tank premixed with salt would make it rise higher because i use a homemade auto refill out of a 5 gal jug and i premix and have not had that happen to me

[carmanimports]

ok so why does my salinty not go i hope it is not that im just lucky

[msbdiving]

How often are you doing water changes and hence adjusting the sg back down? My guess is that if you keep on topping off with saltwater and no water changes, you will see an increase in sg if you take a measurement every day for two weeks. If you need proof, use a 5g bucket and mark it off then only top off with salt water.