https://www.youtube.com/watch?v=-kM1r4_qpYY&feature=youtu.be

we have noticed that the crucible furnace badly effects fps on all versions in the demo above
version Mariculture Deluxe 1.7.10 1.2.4.2a whitch to my recorded is the latest version

Closing as 1.7 mariculture is done, technically the latest dev versions were stable enough and may have fixed it, they just had missing fish textures and docs. I've no idea if this was fixed in them though.