Raising Salinity with Salt ATO

[usfpaul82]

My current salinity is low on my 90 gallon mixed/sps heavy reef. It is currently about 1.023. I understand that getting it back up to 1.026 or 35ppt should be done slowly. I plan to just replace my top off water with mixed salt water, but my question is will I need to adjust or stop my dosing of 2 part while I am topping off with saltwater? Wouldn't topping off with saltwater effectively be the same as also replenishing Alk and Ca?

 

[Randy Holmes-Farley]

The boost to alk and calcium will be about 1 dKH and 50 ppm calcium.

 

[lmm1967]

depends on your consumption and how much evap you have.

In all reality - I wouldn't think it would be a measurable amount.

I just did this after our last vacation - ATO hiccup dropped salinity in one of our tanks while we were out of town.

I had to go from 1.021 back up to 1.026. I did exactly what you are talking about and did not alter anything else and so far the tank is doing just fine.

The setup is about 70 total gallons and my top off uses about 3/4 gallon per day.

It took about 11 gallons of topoff water being at 1.026 to get back to normal. I wouldn't be concerned doing an 11 gallong water change in this system so I wasn't concerned with using 11 gallons ofSW for topoff.

You can use https://www.hamzasreef.com/Contents/Calculators/SaltwaterTopOff.php. as a helpful calculator to assist you with how much water at what salinity you need.

 

[Randy Holmes-Farley]

In all reality - I wouldn't think it would be a measurable amount.

It is easy to calculate.

Going from sg= 1.023 to 1.026 means that everything increases by a factor of 26/23 = 1.13, or 13%. For calcium at 420 ppm, that means it goes to 475 ppm.

 

[lmm1967]

It is, and is easy to calculate.

Going from sg= 1.023 to 1.026 means that everything increases by a factor of 26/23 = 1.13, or 13%. For calcium at 420 ppm, that means it goes to 475 ppm.

Thanks for the details - I didn't choose good words.

I looked at it from the perspective of making the change over the course of 10+ days in a system using both Alk & CA.

An uptick of 13% spread over 10+ days to bring the tank back to where it was previously would not concern me.

OP states he want so bring salinity BACK to 1.026 which indicates he won't really be increasing these numbers when looking at a longer period of time - rather he'll be slowly bringing them back to where they were after a decline.

If that is the case - would you recommend altering dosing schedules?

 

[Randy Holmes-Farley]

I would not be concerned about the calcium rise.

Some folks are very focused on an exact alk, and if that is the case here, I'd suggest altering dosing for a bit.