Cryptocoryne question

[matti]

I've had my Cryptocoryne undulatus in the tank for about 4 months now, and it's been doing great with nice submerged growth. Recently, I added 3 new Cryptocoryne Wendtii with emersed growth, and as expected, they melted after being submerged. However, what's got me puzzled is that my previously thriving undulatus has also started melting. I'm wondering if there's some sort of chemical that plants release that could cause other crypts to melt, or if something else is going on in my tank.

Here's an older pic of my setup - the undulatus is in the closest terracotta pot on the left, and the new crypts are in the plastic pots with Rockwool on the right.

[barnicle]

Crypts can be pretty finicky - they tend to freak out and melt when their water parameters change. No big fan of salt either. Really, planting them would make a world of difference - they'd be a lot happier.

[Aquafan]

Has the tank seen a temperature spike? I've noticed even established crypts can be quite sensitive to temperature increases, often resulting in melting.

[matti]

Has the tank seen a temperature spike? I've noticed even established crypts can be quite sensitive to temperature increases, often resulting in melting.

I keep the tank temp between 20-22c. I'm still puzzled, but it seems the melting happened after I added the new crypts. Maybe their introduction changed the water parameters somehow.