Weird marks on acrlyic tank?

[Northwest_Scapes_]

Hello, so im not sure if this is the right section since the other tank sections are about builds, so if this is the wrong section, my bad.

So these weird marks appeared on the corners of my 50g Seaclear acrlyic after wiping off the polish im using to refurbish it. My dad and I think they could be stress marks since the tank is about 4 years old (we bought it new so I'm the only person who's owned it) it was fine before, could it be from the polish? Im going to test fill it just to be safe, but I think I'll be in the market for a new tank

 

[fishguy242]

hi,following to see if disappear under water ;) looks like on rounded corner,not a prob if don't see:)jmo

 

[Northwest_Scapes_]

Update: Still shows underwater :/
Time to look for a new tank, maybe I'll try out a Waterbox and get my plumbing skills ready

 

[r20crazy]

looks like acrylic crazing (tiny cracks). caused usually by heat, stress, age, or UV light. can also be caused by use of ammonia based cleaners like windex. it will not go away. the polish is probably stuck in the tiny crazing cracks, so u see them more now than pre polishing.

 

[Northwest_Scapes_]

looks like acrylic crazing (tiny cracks). caused usually by heat, stress, age, or UV light. can also be caused by use of ammonia based cleaners like windex. it will not go away. the polish is probably stuck in the tiny crazing cracks, so u see them more now than pre polishing.

Thank you for the clarification. I'm really sad that I can't use it anymore, but I think I found a replacement in a UNS 90U that I'll get next year