What causes salinity to drop?

[lanman]

Okay - the salinity in my main tank is dropping. Does a skimmer take out salt as well as 'junk'?? Where else might it be going? I don't have THAT much salt creep on things. I'm going to have to add water with higher salinity than my tank next water change, instead of lower. Too strange.

 

b0b

[jamal]

yes the skimmer pulls some salt especially when its ran wet. my salinity is dropping as well so im trying to figure out why as well

[YBeNormal]

Normally I'd attribute this to salt creep and wet skimming. In Bob's case, I think it is caused by all of the water you are removing with your constant Alk and Ca testing.

[jason the filter freak]

Normally I'd attribute this to salt creep and wet skimming. In Bob's case, I think it is caused by all of the water you are removing with your constant Alk and Ca testing.

 

Lol

 

I think I once had a discussion with dan while I was at his house about him having to test salinity periodically due to the amount of skimming he does.

[phisigs79]

i usually test mine once every few weeks and add a cup or two of salt to my top off and it usually fixes it. i also add alittle more salt to my water that i make for waterchanges.

[rocko918]

evaporation

[Charlie97L]

evaporation

 

evaporation will cause your salinity to increase, not drop, right?

 

the salt doesn't evaporate, just the water.

[Ne0eN]

evaporation will cause your salinity to increase, not drop, right?

 

the salt doesn't evaporate, just the water.

 

True. In my case I had a slow leak in the overflow tube that was dripping and getting absorbed by the carpet under my tank. I always kept my dosing to keep up what I thought was evaporation. Turns out I was loosing water drop by drop and I was replenishing it with R/O water. Once I noticed the leak and replaced the tube, my salinity has been stable.

 

--Rob

[rocko918]

evaporation will cause your salinity to increase, not drop, right?

 

the salt doesn't evaporate, just the water.

 

 

right but is you have an autotop off you will be dumping more RO water in the tank. Which could bring down the salinity if it is always kicking on.

[Charlie97L]

right but is you have an autotop off you will be dumping more RO water in the tank. Which could bring down the salinity if it is always kicking on.

 

gotcha... i guess that would be a timed ATO, not a valved.

[lanman]

True. In my case I had a slow leak in the overflow tube that was dripping and getting absorbed by the carpet under my tank. I always kept my dosing to keep up what I thought was evaporation. Turns out I was loosing water drop by drop and I was replenishing it with R/O water. Once I noticed the leak and replaced the tube, my salinity has been stable.

 

--Rob

 

Aha! Low salinity caused by squishy-carpet syndrome.

 

About 2 weeks ago I went through a period of time when I was dumping the skimmer every day. So that probably took a couple of gallons out that was replaced with fresh water. I'll bet that is what did it. I'll mix up a little heavy brine, and slide it back up (1.023 - down from 1.025). I'm used to having to add water with about 1.022 to bring it down from 1.026/1.027.

 

Thanks all for your suggestions!

 

And I'll try to cut back on the testing to just once or twice a day.

 

bob

[YBeNormal]

right but is you have an autotop off you will be dumping more RO water in the tank. Which could bring down the salinity if it is always kicking on.

 

????

 

The ATO will only be replacing water that has evaporated. The salt that was in the water before it evaporated is still in the tank so the end result will be the same salinity, not lower salinity. If anything, an ATO replacing small quantities of water multiple times per day will result in more stable salinity than if you only top off once or twice per day.

[bigJPDC]

ka-ching!

[treesprite]

????

 

The ATO will only be replacing water that has evaporated. The salt that was in the water before it evaporated is still in the tank so the end result will be the same salinity, not lower salinity. If anything, an ATO replacing small quantities of water multiple times per day will result in more stable salinity than if you only top off once or twice per day.

 

 

I thought ATO works by water level in the tank, not by whether it was lost by evap or removal (incl. by leaks).

[YBeNormal]

True, and that's what we're talking about, replacement of evaporated water using an ATO. If the tank is leaking and you have an ATO hooked to constant water supply, the ATO will continually replace the lost water and that will result in a gradual decline in salinity.

[lanman]

True, and that's what we're talking about, replacement of evaporated water using an ATO. If the tank is leaking and you have an ATO hooked to constant water supply, the ATO will continually replace the lost water and that will result in a gradual decline in salinity.

In my case - I'm not leaking. I have a concrete floor. I would splash. So I'm guessing it's the saltwater removed during skimming, being replaced with RO/DI water by my auto-topoff.

 

bob