Does Alk solution expand?

[scobeyra]

Weird question. I manually dose on my 30gallon and two different times this year I could swear that I have more solution than the previous time I dosed. Like the fluid expanded to the point I noticed the level increase in a gallon jug. I can rule out tampering since my wife would not / has not opened the stand I keep it in, ever.
First time I thought I was losing it but it happened again.
Anyone have this happen?

 

[Randy Holmes-Farley Verified Community Expert]

It won't expand unless more water is added. It will very slowly absorb moisture on very humid days if left open, but I doubt you can detect that rate of increase.

Water also expands very slightly when it gets warm.

 

[Martin Kuhn]

Additional to what Randy already posted ....

Another reason why you "could see this" is another one.
The PE/PP vessels we use, sometimes simply don't keep its shape.
Im sure some of you also noticed vessels "deflating" if
- the volume gets less
- they change temperature
I call this the vessel (frog) clicker

If the vessels volume gets reduced by this ..... you notice an "increasing filling level" (regarded from the outside, virtually....) Even if the volume of the content inside stays the same, the water level rises.

 

[LobsterOfJustice]

Are you manually dosing this to your tank or are you using a dosing pump? If you're using a pump it's possible solution is draining back into the bottle from the line or even siphoning water back from the tank.

 

[scobeyra]

Additional to what Randy already posted ....

Another reason why you "could see this" is another one.
The PE/PP vessels we use, sometimes simply don't keep its shape.
Im sure some of you also noticed vessels "deflating" if
- the volume gets less
- they change temperature
I call this the vessel (frog) clicker

If the vessels volume gets reduced by this ..... you notice an "increasing filling level" (regarded from the outside, virtually....) Even if the volume of the content inside stays the same, the water level rises.

This makes sense. It's a thin plastic bulk reef supply jug. Could easily expand and contract

 

[scobeyra]

Are you manually dosing this to your tank or are you using a dosing pump? If you're using a pump it's possible solution is draining back into the bottle from the line or even siphoning water back from the tank.

I'm manually dosing this tank so no back draining