200 gallon tank replace?


New member
10 year old FOWLR tank has some white patches on each side of the tank. please see pictures. is it time to replace the tank? I don't see any leaks though. what's the average lifespan for a tank? Thanks for your time and guidance.
Unfortunately the answers you will get to this type question are more or less going to be based on people's risk tolerance - from "it's no problem" to "replace it now".

It really comes down to how you feel about it. If that's been getting progressively worse and it affects your sleep, then you should replace it to rest easy. If it's looked like that unchanged for 2 years and the silicone is still flexible then it's probably not an emergency.
Weird, I’ve never seen anything like that in all my years in the hobby. At one point I had a 200 gallon Oceanic that was probably 15 years old.
Thanks karma and griss for your inputs. I forgot to mention that this is an acrylic tank and it's not level but leaning forward half an inch at the top when compared to the bottom of the tank so I was wondering if after draining the water and leveling the tank would it be worth to keep it for another 5 years or so. I browsed the forums and it looks like issues like tank breaking mostly happen with glass aquarium so wondering if anyone has any inputs for acrylic tank.


  • IMG_20230116_171704.jpg
    1.7 MB · Views: 5
While it seems significantly rare for acrylic to burst, it can happen, though usually more of a seam leak more than just a outright burst. With that said, what size tank are we dealing with? If it were me, I would reach out to a local acrylic manufacturer to get their opinion. I’m with @griss that I don’t like stress marks but they are likely caused due to the tank being unlevel and age. I don’t believe it would hurt to try to get the tank releveled but it’s just my opinion
Ya, I have zero experience with acrylic but that does seem scarier. Crazing aside, what's happening in this spot I circled, is it separating?

Thanks everyone for your inputs. I'm not really sure what's going on with the tank but it does look like the front under lot of pressure due to the tilt. For now I have moved the fish to a brute can and the live rock in another and have drained out most of the water as I guess it's better to be safe than taking unnecessary risk. Even with all the water out the aquarium is still tilted so may have to shim it under the stand but currently reaching out to aquarium builders and acrylic tank companies to see if they can help fix the tank.