specific gravity

[trevbo44]

My salinity level is constantly through the roof. Is it solely from evaporation? In the last month I have changed roughly 30 gallons in my 75 gallon system with only RO water! No salt!
The tank is steady at 78 degrees. I do, however, put Pro dKH buffer in as well as Purple up. The dKH is at around 5 and the Ca at around 300. I can't seem to get them to rise but I have heard that they may impact evaporation rates. Any suggestions?

 

[Anonymous]

How much does the specific gravity change per day?

1 gal of top off per day for a 75 gal tank is not excessive if the air is dry, temp is high, and good air circulation.

BTW, adding RO water to tank is top off. It performs different than water change, and these tasks are not interchangeable.

 

[sidd129]

What are you topping off with. Salt doesn't evaporate so you should top off with ro/di (no salt in water). Did you do a 30 gallon change, as in all at once.

 

[rbursek]

If your Mg is low it is hard to get and keep Ca up. What is your Mg?