Needing help with my salt levels - keeps going up

[ashr]

Hey all

So some background first. 66g red sea max. heavy SPS and LPS corals.

Id like my levels around 1.026 but found it was around 1.030 today when I checked. I only top off with fresh R/O water but sometimes the top off is around 2-5 gallons. I do a water change every month (I know I know but this works well for my tank) Whenever I do a water change I only add water with a salt level of 1.015 to 1.020 to help lower it in the main tank but it only goes down a bit once I add it but it always creeps back up..

Any ideas why?

I dose Mg, Calc and Alk.


Thanks!

[mike31154]

What are you using to take the salinity readings? Refractometer or something else?

[George]

Dosing Alk can and will increase your salinity/SG. Depending on how much you dose and what your tank volume is, it's possible that SG increases from 1.026 to 1.030 in a month. Check your salinity often and adjust it by taking out salt water and replace it with fresh water.

[ashr]

Refractometer is what I use and I always make sure it is calibrated.

I didnt think about the Alk as I have a lot of SPS do I dose a lot.. Ill cut back and check my levels more often.


Thank you !

[RumRunner]

Yup time to calibrate

[The Grizz]

We have a large amount of evap in our house and my salinity can climb fast if I don't keep my ATO full at all times ( never let it get below half full ). Could be an option to check as well.

[Rodney]

2-5 gallons is a hefty top off , it wouldn't be surprising to see that size of an increase with a tank that size my tank is 125g with a 90g sump the top of is about a gallon every 10-12 hours on a DIY auto
Also how long is your water change water sitting before you do it, I found if I check it when I mix its lower than 12-24hrs later when I use it