# Black spot on bottom of resin tank

**URL:** <https://forum.formlabs.com/t/black-spot-on-bottom-of-resin-tank/29068>\
**Category:** Form 3/3+\
**Created:** [October 16, 2020, 11:32pm UTC](https://forum.formlabs.com/t/black-spot-on-bottom-of-resin-tank/29068 "2020-10-16T23:32:41Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![SarahAStClair](https://avatars.discourse-cdn.com/v4/letter/s/3bc359/32.png) [@SarahAStClair](https://forum.formlabs.com/u/SarahAStClair)\
**Post date:** [October 16, 2020, 11:32pm UTC](https://forum.formlabs.com/t/black-spot-on-bottom-of-resin-tank/29068/1 "2020-10-16T23:32:41Z")

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Hello,

We’re seeing a large black spot on the bottom of our Form 3 resin tank. It’s completed ~99 small prints but on past tanks we’ve completed many more without failure. We recently changed which Form 3 printer this tank/resin is loaded in, and I believe we saw this failure on the next print. Has anyone seen a similar issue?

 ![IMG_8506](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/3X/5/7/572e413b7949c19c6d54168a395629bb4dcf7576.jpg)

 ![IMG_8504](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/3X/c/2/c2d2eaf8c62dfc2ca2ab970f48b664580844a382.jpg)

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**Author:** ![leonhart88](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/leonhart88/32/19153_2.png) [@leonhart88](https://forum.formlabs.com/u/leonhart88)\
**Post date:** [October 16, 2020, 11:52pm UTC](https://forum.formlabs.com/t/black-spot-on-bottom-of-resin-tank/29068/2 "2020-10-16T23:52:03Z")

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This means there’s a small puncture in your tank and resin is leaking between the film layers. Highly caution against continued use of that tank!