PLS REFER TO THESE VIDEOS TO GET THE CONTEXT
This molly started wiggling like this...then all other mollies started wiggling(THE SAME CORNER!!)....then all of them started to die back to back without a sign (sudden deaths....just fine yesterday,..found dead today morning)....this happened like a few months back....and all my mollies died...
now i got another 2 pairs of molly (around a week) and they started wiggling in the same corner again and i am afraid that they would also die
tank dimensions LxBxH = 20x12x18 INCHES....tank well cycled....all the values of ammonia,nitrite and nitrate are well under control...ph at 7.2 (back then....and now too)
i dont this the plastic plants are the issue (i tried removing them...no difference)(the mollies did not act like this when i had them in a smaller tank-5Gallons)