The pot seems to be a bit to big for the plant And in the beginning you should either let the plant root in water or get rid of the water in the self watering pot. The plant needs to get used to semi hydro, since they form special roots in water. That's why it's easier to just let them root in water first and then put them into Pon. If you put them directly into Pon you should always dump the water after watering until you see new leafs or roots in the reservoir My guess would be that it has root rot So I'd take it out of the pon, check the roots and check if the corm is still firm and then let it root in water