YOU DO NOT NEED A HOSPITAL TANK you need to treat ich in the tank as it lives in the gravel
you should not be removing the filters from you tank
you only need to remove any carbon or zeolite that are in the filters
removing the filters will cause ammonia or nitrites in your tank and kill your fish
every time you are removing your filters you are destroying any beneficial bacteria that are in them thus you have to restart a fish in cycle which
what size is the tank and what stocking do you have at the moment
please read this link about fishless cycling
<a href="http
/www.fishforums.net/index.php?showtopic=113861" target="_blank">http
/www.fishforums.net/index.php?showtopic=113861</a>
- if all your fish are dead do not replace them unless you are going to do a fish in cycle
TO TREAT THE FISH
do a good gravel vac and water change first - removing 50% of the water and replacing with dechlorinated water near enough matching the same temp as your tank water
remove any carbon and zeolite from you filters - but do not remove the actual filter
turn the temp up to 30 degrees
add the meds
increase aeration by adding an airstone to the tank
then in 7 days do a 50% water change and re dose if necessary
have you tested your water for ammonia , nitrites , nitrates and ph
if not please invest in a good liquid test kit API master is approx £20
and will help you with the cycling process as it will let you know when the levels rise so telling you when you need a water change
Ammonia and nitrites are both poisonous to fish
how often do you do a water change now?
(i hope thats easy to understand i have tried my best but my MS head is not good at the moment)
please get back with anymore questions thanks sarah