The best thing you can do to prevent HITH is to do large and frequent water changes and keep the diet varied and nutritious (some suspect vitiamin deficiency as a probable cause of HITH). I'm guessing that your water changes aren't frequent nor large enough so I'd up the quantity of water you change and the frequency.
Heximita, the suspected cause of HITH, does not do well at higher temps and metronidazole will help greatly. It's suggested that you get the temperature up to at least 92. I'd put the metro in their food as that is the most effective way for metro to work. You can also purchase treated flake food from Angels Plus. Here is a link: http://www.angelsplus.com/FlakeMedicated.htm You will want the Anti-Protozoan Flake. Many people swear that it's the best thing since sliced bread.
Heximita, the suspected cause of HITH, does not do well at higher temps and metronidazole will help greatly. It's suggested that you get the temperature up to at least 92. I'd put the metro in their food as that is the most effective way for metro to work. You can also purchase treated flake food from Angels Plus. Here is a link: http://www.angelsplus.com/FlakeMedicated.htm You will want the Anti-Protozoan Flake. Many people swear that it's the best thing since sliced bread.