Can’t Clean used Reef Tank Glas :/

[twentyleagues]

It’s actually not a deposit it’s the opposite. It’s etched.

Yup its over my head for sure whatever it is. I just know cerium worked when nothing else did. While I like the 30g I doubt if /when I break it down again I will put this much work into it to clear it up. It cost me $75 with stand brand new, (empty display) had sat in the lfs for 3 years no one bought it. It has gone through quite a few builds in the 5 years I have had it.

 

[GlassMunky]

Wow thank you very much for all your Posts. Very helpful !
I am now going to buy a cerium oxide set with a drill connection. I think 400grit sandpaper will be fine ? Should I sand wet ?
And should I sand by hand or also with the drill ?
Thank you

cerium oxide is more like 2000 grit..... 400 will leave crazy scrathes in your glass....
When i grind glass for work we start at 200, then 400, then 800, then 1200, then cerium oxide polish is the final step.
Polishing with cerium oxide actually kind of "melts" the exterior of the glass making it shine whereas every other pad is just making smaller and smaller scratches. the cerium actually heats up and causes the reaction.

 

[GlassMunky]

keep in mind, if you polish it with cerium in just a single place or in a line, that part of the glass will be slightly thinner and may cause some optical distortion

 

[Randy Holmes-Farley]

I would use a physical abrasive as a very last resort.

 

[Dom]

It’s actually not a deposit it’s the opposite. It’s etched.

Can you tell that from the picture?

OP did say that it disappears when the tank has water. Maybe leave it as is instead of risking making it worse.

 

[SteveMM62Reef]

If it was used for Salt Water you have Alkaline Etching and no Acid is going to correct this. You will need a VSR Right Angle Drill and this.

Glass Polishing Kit, Cerium Oxide Polishing Powder Felt Polishing Wheel Set for Windscreen and Glass
https://a.co/d/0Yr6Xrf

 

[The_Paradox]

Can you tell that from the picture?

OP did say that it disappears when the tank has water. Maybe leave it as is instead of risking making it worse.

Cannot tell from the alone photo no. Going by appearance coupled with the fact strong acids are not removing it. It’s a common problem with glass in not just tanks but also windows. Depending how bad it is, it can be a few seconds of polishing per area or a few minutes.

 

[Randy Holmes-Farley]

If it was used for Salt Water you have Alkaline Etching and no Acid is going to correct this. You will need a VSR Right Angle Drill and this.

Glass Polishing Kit, Cerium Oxide Polishing Powder Felt Polishing Wheel Set for Windscreen and Glass
https://a.co/d/0Yr6Xrf

Not sure why you equate salt water (pH ~8.2) with alkaline etching of glass. My tank glass was in salt water for many years and showed no etching.

 

[The_Paradox]

Not sure why you equate salt water (pH ~8.2) with alkaline etching of glass. My tank glass was in salt water for many years and showed no etching.

I’ve never given it much thought as I always just assumed it was an interaction with the iron in the glass. You only place I’ve ever seen it is where there is a neglected area such as scum line or under coralline. If it was just the scum line I would dismiss it as a deposit. If you take another piece of glass and some dye you can actually confirm that whatever it is is subtractive not additive.

 

[SteveMM62Reef]

Not sure why you equate salt water (pH ~8.2) with alkaline etching of glass. My tank glass was in salt water for many years and showed no etching.

Because I took a 15 gallon Aquarium that had Hazy Glass to a local Family owned glass shop. They told me it was either Acid or Alkaline Etching. Since it was Saltwater, said Alkaline Etching. Also said Plate Glass has a Hard Side and a soft side with Micro Pitting. Soft side is more Vulnerable to Etching

 

[Randy Holmes-Farley]

Because I took a 15 gallon Aquarium that had Hazy Glass to a local Family owned glass shop. They told me it was either Acid or Alkaline Etching. Since it was Saltwater, said Alkaline Etching. Also said Plate Glass has a Hard Side and a soft side with Micro Pitting. Soft side is more Vulnerable to Etching

Ok, I believe it was possibly etched, I just would not believe the glass guy knows anything about the ability of seawater to etch glass due to the pH. It takes pretty high pH to etch glass.

 

[G&B Reefing]

Haven’t read all 4 pages worth. I have a max nano that is currently running. I have the same “staining” in the same spots. I go after it once every 2 weeks or so with the algae scraper… it comes off but takes a bit of effort. My guess is either salt or calcification at the top of the water line. It will come off but you may need to apply some sweat and elbow grease. Fyi i use a metal blade scraper, plastic ones are garbage and wont take it off.

 

[exnisstech]

I think you may end up buying a roll of black vinyl tape to hide it, if nothing else works. It may look quite smart anyway.

Ding ding we have a winner! This is the easiest and you never have to look at the water line. I did it on my new building and like the look so much I did another. What ever you scrub off is just going to build up again once the tank is running.

 

[carol3]

Lol I wonder how big those are? He currently is about 8-10" and live peacefully with 2 about the same size synodontis catfish. I dont want him tearing them up. So probably not the best idea to teach him to kill larger fish. The guppies can be food I am ok with that. I just dont like when he hunts them just to kill them and not eat.

I have a pea puffer tank and thats exactly what they do with snails and shrimp, eat till you are full then just kill for fun!

 

[twentyleagues]

I have a pea puffer tank and thats exactly what they do with snails and shrimp, eat till you are full then just kill for fun!

I had a group of them too, 2 males 10 females they were good for about a year then the males started killing the females eventually got down to 1m 3f. Heavy plants, wood, and rocks. I ended up trading them in at the lfs as they wouldnt eat anything but live black worms and occasionally a small ramshorn. Crazy little murder beans.

 

[s3leyman]

Thank you everyone for youre Posts / Advices !!

Here Are my First Results: i sanded the Glas first (but it looked Like sanding had no effect on the glass. Did it with 2000, 1600, and even 1200 grit)

Then I used my drill.. started with the white ceriumoxid and finished with the red ceriumoxid

Before and after:

 

[mrjoe]

0000 steel wool... I use it to clean my windows on my car and home.... also works great on chrome.... NEVER a scratch.... you can use it wet one time or dry.... up to you...