I have read on this site where people state that in order to keep salinity at a constant level as water evaporates from the tank on a daily/weekly basis it should be topped off with RO/DI water or distilled water since only the water evaporates from the tank and not the salt. So by topping off with salt water you are basically increasing the overall salinity. If this is so; what is the reason for the salt accumulations that sometimes appear around the top of my tank. Is this not salt leaving the tank? Please explain, thanks.
water evaporation
- Thread starter thekidace
- Start date
dark_stranger
New member
The salt deposits you are seeing around your tank is called salt creep & even though you are correct in stating that this is leaving your tank, its not on the scale of water leaving your tank & therefore the salt to water ratio leaving your tank is low. Therefore that why you only top up with RO water as otherwise over time your SG will increase adn cause harm to the tanks inmates.
dark_stranger
New member
Yep & then when/if you perform water changes you would use salt water that would in turn be used to adjust SG & also replenish trace elements, etc
rustybucket145
New member
Exactly right, RO/DI for top off. And saltwater for water changes.
Alaskan Reefer
New member
Concur -- RO/DI for top off, SG matched / temperature matched / aerated saltwater for changes.
angelsj247
New member
what you see around your tank is salt creep.. which is if the water splashes out of your tank or drips.. the water evaporates but the salt stays there since salt doesnt evaporate, thats what you see. am i correct?
AZDesertRat
In Memoriam
Exactly. Alaskan Reefr also forgot to mention when you change water make sure the pH is matched to the tank water. pH is often overlooked and misunderstood but is very important.
guyguerra
Premium Member
There is another option to pure water top offs. I have a storage tank in my garage that I mix my salt water in, then it's pumped into the tank for changes (see picture below). I keep my storage water at .024, so when I do my weekly changes it averages out to between .025 and .026. It's not a science, though you could calculate the amount of evaporation and the amount of water in the change to come up with a factor that would put it back to your desired number. This wouldn't help if you don't change water often, but theres a noticeable difference when you do 10% weekly changes. Once every month or two I have to add straight water, but in my 230 gallon tank, it's usually only 2 gallons when I do.
