Specific Gravity

[90galguy]

I know this is probably a pretty basic question but here it goes anyway.

My system uses about 1.25 gallons of ATO each day with fresh RO water. With that being said I've watched my SG drop ever so slightly from 1.026 to 1.024. Since this is a brand new system, I assume this is a standard drop which would be taken care of during weekly water changes, which I of course haven't started as of yet.

Is this theory correct? I just wanted to confirm that I'm thinking correctly and that there isn't another way of keeping my SG stable between water changes.:wow2: I also realize that I'm being very anal about my numbers.

I will relax somewhat down the road. :lol2:I just want to make sure I'm understanding the affects.

 

[grouper therapy]

Salinity should not change during the week with an ATO . Your water is not sneaking out the safety overflow is it?

 

[izoid]

Salinity will typical stay stable as long as you top off with RO. I have not seen mine fluctuate as long as I top off to the same level each time. Is it possible that you are adding too much top off each time?

 

[90galguy]

My ATO is gravity fed and so far I've estimated that I'm adding 1.25 gallons a day. No leaks either Grouper!:thumbs:

 

[porpoiseaquatics]

SG will also fluctuate with temp changes.

 

[grouper therapy]

wHAT ARE YOU CHECKING IT WITH?

 

[lilrobb]

Mine drops ever so slightly over some weeks too, it's the salt creep and the wet skimmate for me, though...

 

[grouper therapy]

lilrobb;713485 wrote: mine drops ever so slightly over some weeks too, it's the salt creep and the wet skimmate for me, though...

good point!

Edit:

LilRobb;713485 wrote: Mine drops ever so slightly over some weeks too, it's the salt creep and the wet skimmate for me, though...

GOOD POINT!

 

[90galguy]

My Ranco controller has my temp pegged at 77.

And I am getting some wet skimmate as well.

 

[ff337]

What are you checking it with. Possibly you need to recalibrate. Rmember to calibrate with a known medium closest to what you test with.

 

[90galguy]

BigJohn;713567 wrote: Probably the wet skim. With evaporation the salt stays when the water leaves. You are probably losing salt with water changes. Maybe you are not adding enough salt when you mix or maybe it is not all dissolving. Or maybe you should try another hydrometer.

My mix will always be 1.026 and 77 before I add it, however I haven't made a water change as of yet. I'm only 3 weeks in to my cycle. I'm aware of the salt being left behind during evaporation, but I hadn't thought about the wet skimmate.

Edit:

grouper therapy;713483 wrote: wHAT ARE YOU CHECKING IT WITH?

I'm using a refractometer calibrated by Jenn. I'm sure it's pretty accurate.

 

[90galguy]

BigJohn;713664 wrote: How big is the tank? How much wet skim do you get a day?

Probably jot enough to make a dent in the SG. If I crank it up I'll get 2-3 cups. I'm on week 3 of my initial cycle. Is a .002 drop within that timeframe an issue?

Sent from my PC36100 using Tapatalk