Having difficulty getting my salinity to go up.

[Powahfull]

I am in week 6 of my biocube32 gal. I have only ever gotten water from a coral store. They are 25 (1.025?) my salinity slowly drops down 23 every water test every week I do a 5 gallon water change and the next week it's 23 again.

Why won't it go up? Should I have them mix like a batch of 27 salt and try that?

 

[PeterC99]

What are you using to test salinity? Is it properly calibrated?

 

[Rmckoy]

I am in week 6 of my biocube32 gal. I have only ever gotten water from a coral store. They are 25 (1.025?) my salinity slowly drops down 23 every water test every week I do a 5 gallon water change and the next week it's 23 again.

Why won't it go up? Should I have them mix like a batch of 27 salt and try that?

Do you run a ato ?

the only way salinity can drop over time is adding too much freshwater .
or adding freshwater to compensate the water taken out by skimming .
Salt doesn’t evaporate , but the water does leaving the salinity in tanks higher from evaporation .

Example : on my 230 I have a external skimmer , and a ato

the ato pumps freshwater in to compensate for both evaporation and water taken out from the skimmer .
After a week my salinity drops from 1.026-1.024

 

[Rmckoy]

Testing equipment such as a refractometer that hasn’t been calibrated

testing error

 

[Powahfull]

I am not 100% sure what the guy uses but I bring in a little less than half a mason jar of water. He just sticks like a thermometer in it and it digitally tells him.

I don't run any top off it's a stock Biocube32 no top offs the water level doesn't really drop I keep it closed mostly. By the time the week comes around I just siphon out slightly less than the 5.3 gallons I fill so most likely 5 and the water level is always full I don't need to add top off water.

 

[Rmckoy]

I am not 100% sure what the guy uses but I bring in a little less than half a mason jar of water. He just sticks like a thermometer in it and it digitally tells him.

I don't run any top off it's a stock Biocube32 no top offs the water level doesn't really drop I keep it closed mostly. By the time the week comes around I just siphon out slightly less than the 5.3 gallons I fill so most likely 5 and the water level is always full I don't need to add top off water.

That’s strange ..
a week and no evap at all ?

he’s most likely using a conductive meter ( Hanna salinity pen )

they are ok but still need to be calibrated often

 

[srobertb]

Bring him 2 jars. One with freshly mixed SW and one with 2 week old water.

Temperature can throw off salinity readings (among other things).

Especially in small all-in-ones: tiny things like blocked overflows, dirty pumps, dirty filter socks, a shift in heater placement that slightly inhibits flow, a bag of media shifted slightly…so many things can change flow rate through what equates to a tiny sump causing the water level to change and the ATO to add more water.

I waited way to long to purchase a Milwaukee digital refractometer. It’s $100. It is so simple to use. I’m “that guy” who had to buy the petsmart version, the eye glass version, then finally get a digital one. Just get a digital one.

 

[Powahfull]

It's mostly an invert tank of different hermit crabs here's a baby blue leg with a giant scarlet and behind a regular red leg. There are other things in the tank could the invertebrates some how be using the salinity some how? Also a Halloween hawiaan and a banded eye.