Tiny cracks on acrylic?

I found these tiny cracks/ scratches on the front of my tank. They don't bother me, but they would probably bother me if I came home to a 40 gallon mess. What are they and do I need to worry about them? 
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Well, they are either scratches or what's called crazing. If it was cracks they would be deep and visually noticeable going mostly all the way through the acrylic. Crazing is a type of stress fracture that's ONLY on the surface of the acrylic.

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They look to be only on the surface, is crazing something to worry about?

The scratch in that link looks more like a scratch, these are more symmetrical or straight  

Missgrumpygills wrote:They look to be only on the surface, is crazing something to worry about?

I dont think so Missgrumpygills. I believe crazing is just aesthetic and doesn't get any deeper than the surface of the acrylic. I remember other forum members discussing it but for the life of me cannot find the thread using the search menu.

fishNAbowl wrote: I believe crazing is just aesthetic and doesn't get any deeper than the surface of the acrylic. 

 If this is true then i'm relieved, its only in one area and I don't really notice it while i'm watching my fish.

Missgrumpygills....hard to tell what you have going on there without seeing it in person. We had two acrylic tanks previously and had some crazing on them.  Crazing is usually more concentrated and has a bit of stretched look to it.

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Acrylic scratches very easily.  If its a scratch you will only feel it on one side of the tank (usually the inside of the tank).  One of our tanks had scratches all over it as my husband picked up a piece of shell in the magfloat and played tic-tac-toe on the front of the tank during a cleaning session.  Scratches will look like this (not our old tank but shows what scratches look like)

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Can you feel the marks on both sides of the aquarium...inside and out?  If you can then it is a "crack" as a crack will go "through" the acrylic. Here's what a crack usually looks like or the line will also have a "star" effect where you have the deeper cut and some lines radiating out from it

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Scratches are not things to worry about.  Cracks are and crazing you just need to keep an eye on it as it means there is a weakness in that area of the tank.  If it grows you would possibly want to replace the tank.

I cannot feel them on the front of the tank, I will have to check if I can feel it on the inside. There are some that have small symmetrical lines radiating from them

My 125 has crazing all over the front...... It's visually not very pleasant but hasn't ( knock in wood) affected the structure of the tank in the year+ I own it.

I've heard you can get rid of them by using the same process that people use to fix their head lights, though I have never tried

Can glass tanks get that too? Or its just scratches? [You must be registered and logged in to see this image.]

Glass scratches but never as easily as acrylic. And glass, when it's cracked will "star" just like you see on your windshield when a rock hits it and it cracks or break clean through. Glass scratches are much harder to remove than acrylic scratches and certain lights show the scratches more than others...I can't remember which way it goes...LED's show more I think and T5/T8's less? or vica versa

Those are scratches Wes...I know...I had em but I didn't make em...tank came that way to me too

I can live with scratches. Not cracks. Thanks for your response.

Have you guys ever tried the colgate and silicon tricks? I've been curious about these for a while.
colgate: [You must be registered and logged in to see this link.]
silicone (and buff): [You must be registered and logged in to see this link.]

The toothpast trick works ok on Acrylic but not as fast 3 stage Novus. It is about a 1/4 of the cost though 10x the sweet equity.

lloyd378 wrote:My 125 has crazing all over the front...... It's visually not very pleasant but hasn't ( knock in wood) affected the structure of the tank in the year+ I own it.

I've heard you can get rid of them by using the same process that people use to fix their head lights, though I have never tried

Yep I used a Mother's headlight restoration kit to restore my used 55 gallon.  Worked great, even on some deeper scratches.  As an aside, when I was done with the tank it gave me motivation to go and actually use it on my car's headlights.

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Thanks for the tips guys