Here is an article on HITH http://www.duboisi.com/diseases/hith.htm
There is no conclusive explanation on what caused HITH. Hexameta was once blamed for the desease, but it is now believed to be present by oppotunity after the pits were formed. So eliminating the Hexameta may have no effect on HITH. I have a strong belief that HITH is species specific, because some cichids, such as African Rift Lake cichlids, never get it. They just die from bloat or other deseases if the conditions were wrong.
There is no conclusive explanation on what caused HITH. Hexameta was once blamed for the desease, but it is now believed to be present by oppotunity after the pits were formed. So eliminating the Hexameta may have no effect on HITH. I have a strong belief that HITH is species specific, because some cichids, such as African Rift Lake cichlids, never get it. They just die from bloat or other deseases if the conditions were wrong.