Precipitation at Waterline

[Saintnovakai]

I keep getting this hard precipitate at the waterline. It's not salt. I have to use a blade to scrape it off. My Alk sits at 8. Calcium is 410-420. Its not coralline because it's only at waterline. In all honesty, I don't get much coralline growth perse.

What's going on with the waterline?

 

[Gareth elliott]

Besides sodium chloride, you can also get other salts, like calcium carbonate, or magnesium salts.

 

[Saintnovakai]

Besides sodium chloride, you can also get other salts, like calcium carbonate, or magnesium salts.

But only at waterline? Why only there? I figure it's calcium but again. Why only there?

 

[Gareth elliott]

But only at waterline? Why only there? I figure it's calcium but again. Why only there?

At the waterline is where water evaporates, as the water turns to steam it leaves the dissolved particles behind.

 

[Saintnovakai]

At the waterline is where water evaporates, as the water turns to steam it leaves the dissolved particles behind.

That actually makes perfect situational sense. I'm blasting fans at the surface. Good catch! I was starting to think pH was too high from the new Randy's Two part.

Thanks man!

 

[Gareth elliott]

That actually makes perfect situational sense. I'm blasting fans at the surface. Good catch! I was starting to think pH was too high from the new Randy's Two part.

Thanks man!

Np

 

[rkpetersen]

At the waterline is where water evaporates, as the water turns to steam it leaves the dissolved particles behind.

Also, the more surface agitation and air flow you have, the more this will happen -
As the surface gets wet, water evaporates and calcium carbonate precipitates, surface gets wet again, etc.
And, the higher you boost your calcium and alk levels, the more precipitation you'll get.
It can be very hard to remove if left for a while. Even using a good bit of force with a metal algae scraper.
And if you work too hard to remove it manually, you can wind up scratching the glass, especially low iron glass.
You can dissolve it away with acid, but this isn't particularly practical with a running tank.

 

[dragon99]

I often use a magic eraser sponge on the buildup during a water change. Dip the sponge in a little vinegar for added scrubbing power, the little bit of vinegar that gets into the tank won't be a problem.