Salinity And Gravity Rising

[karmagl]

I have had my 120 gallon salt water tank running for about a month. We don't have fish yet. All of our level have been fine and then last week we bought some already cured lived rock some crabs and some snails. Now the salinity and specific gravity keeps rising. I just keep doing water changes without salt. Is this normal, do I just keep adding non salt water to keep it down?

 

[brittlestar]

Maybe your hydrometer is broken? maybe get another one or take some tank water to your LFS to test it? I don't see how it'd rise

 

[boshank23]

you measure SG (specific gravity) of the water to determin the salt levels in the water. the only way the SG will rise is through evaporation, as your water evaporates it will leave the salt behind making your SG rise.

if you have a awinging arm hydrometer ditch it in favour of a float type or a refractometer

 

[N1z]

Do you wash your hydrometer in freshwater afterwards testing? Could be that your getting salt deposits on the swinging arm causing to rise.

When changing the SG through water changes make sure you do it slowly, as it can cause issues with fish and corals but thats later on when you have some .

 

[lavalamp]

Have you just installed your heaters?

Don't forget salinity increases as the tempreture increases!

Lavalamp.

 

[SkiFletch]

And are you replacing evaporated water with pure water?

 

[Lyle]

my 55 gallon does this too. just remember that when water evaporates, salt doesn't. my sg goes from about 1.023 to 1.025 every week or couple days even. i just put more freshwater water in, or do a water change till its back to 1.023. The more water that evaporates out of your tank before you put more fresh water in, the higher the sg is going to be.

 

[afmo]

My tank does this as well. all tanks will have small rises in SG. Its just the nature of salt water. how big of a swing are you talking about and how often does it occur? I agree though the type of hydrometer you are using is important and something that is often overlooked. I'd have your LFS check your SG with their equipment against yours and make sure its reading properly. also, do you have a lid or an open top aquarium?

 

[karmagl]

That makes sense because we just have a cover and lose about 2-3 gallons a day due to our altitude. New prob though or at least I think. We put our rock in and everything was turning beatiful. Now we are getting this freaky brown hair like stuff growing everywhere is that normal.

 

[callell]

You tank is just going throught the normal stages of development

Algea is a horribel part of it

Check you phosphate levels & add a phos remover

 

[karmagl]

Ok well we added salt 3 months ago when we first added water. Since then we have only added fresh water no salt and we are at the top of the red it reads 1.025. How often are you supposed to add salt water it's always so high we haven't added salt in 3 months and we add 2 gallons of fresh a night. Are we doing something wrong.

 

[afmo]

Ok well we added salt 3 months ago when we first added water. Since then we have only added fresh water no salt and we are at the top of the red it reads 1.025. How often are you supposed to add salt water it's always so high we haven't added salt in 3 months and we add 2 gallons of fresh a night. Are we doing something wrong.

big distinction here, are you adding 2 gallons of fresh a night to bring down the SG, or are you evaporating 2 gallons a day and filling your tank back up at night with fresh?

if your tank is open top, then your evaporation is going to be even more so. if you have an open top, you might consider a glass or plexi lid to curb your evaporation....

 

[callell]

Ok well we added salt 3 months ago when we first added water. Since then we have only added fresh water no salt and we are at the top of the red it reads 1.025. How often are you supposed to add salt water it's always so high we haven't added salt in 3 months and we add 2 gallons of fresh a night. Are we doing something wrong.

big distinction here, are you adding 2 gallons of fresh a night to bring down the SG, or are you evaporating 2 gallons a day and filling your tank back up at night with fresh?

if your tank is open top, then your evaporation is going to be even more so. if you have an open top, you might consider a glass or plexi lid to curb your evaporation....

Adding a cover to the top of you tank will drastically cut down the light that penetrates to the tank, covers are not popular in marine keeping

Are you using an auto top up to replace the water as it evaporates

 

[afmo]

Adding a cover to the top of you tank will drastically cut down the light that penetrates to the tank, covers are not popular in marine keeping

this is true, but depending on whats in the tank and their light requirements, a lid might be a better alternative than having to replace 2 gallons of water a night. With that much fresh water turn over, you're opening yourself up for problems. The biggest issue i could see being that at the rate he's going, he won't be able to leave the tank for a night without running into problems. Assume you miss a night and lose 4 gallons of water, an SG swing from the resulting evaporation could stress fish and coral, and even kill them...

like i said, it depends on the light requirements for the tank, but it might be a lesser of 2 evils situation to combat that much evap...

 

[karmagl]

Yes about 2 gallons evaporate every day so I add fresh. We don't really want to go for the top because we are starting a reef tank and have some coral already.