Friends don't let friends...

Acrylic can craze like that from cleaning fluids. Very bad to use chemical cleaners on acrylic. Maybe someone thought they would do you a favor and clean it with windex?
 
I have had the same exact system for 6 months. Never a problem. I have had the same fish and everything i spray windex on a microfiber cloth so it doesn't scratch. That looks like someone pushed and flexed the back of the tank so it looks like stress cracks. I have heard acrylic is stronger than glass. Marineland should replace it as their customer service is top notch.
 
WOW

Wow what did marineland say? did you contact them? I have the same kind of tank only the 5 gallon version from Walmart...minus the eclipse logo but everything was made by eclipse...I was cleaning my tank and saw a few scratches...so i then buff the plastic to remove the scratches...then before I put water in it...I wanted to remove the chemical from the rubbing compound....I used rubbing alcohol(big mistake) and suddenly I see the same micro cracks thats on your tank...I freaked out...but I filled it with water and it didnt leak so the tank is still okay on my table right now...did yours leak? or you just noticed the cracks? These tanks are made of a brittle plastic...I wouldnt call it acrylic as in the same type as Sea Clear or CLear for life etc...those you can tell is plexiglass...
 
Definitely worth contacting the company. I did that with a tank I picked up at the dump once. The lighting fixture wasn't working and I got in touch with the company to see how to go about purchasing a replacement.....they offered to replace it for free, even after I told them I didn't buy it and had picked it up at the dump !

I was told..."Doesn't matter, we guarantee our products, we'll have a new one out to you soon". I didn't just recieve one, but two...someone goofed and they sent me two brand new lids. I contacted the company to let them know of the error...do they want me to send it back to them ? "Nope, keep it, our mistake"

Always check up...you never know !
 
AquariaCentral.com