Flowerpot won't live even for experts.
For the rest, you have too many phosphates: have algae? If yes, you have more than .25.
your salinity should be 1.025. Your calcium should be 400-450. Probably your magnesium is way low, to have calcium that low [they're related.]
WHoever said 4 weeks for ich was unfortunately wrong: it's 6-8, and with the luck you've had, go long.
First, set up a quarantine tank and use it religiously for your next fish for 4 weeks---especially for fish from a source that has given your tank ich once already. Leave your main tank fishless for 8 weeks.
Fix your water, and get the temperature stable at 80. Shoot for 7.9-8.3 ph, and 8.3-9.3 alkalinity. Set up a routine for tests and water changes, and log your test results so you're dosing INTO the trend, not dosing to try to make up for a bad situation.
Clowns are notorious for two diseases: ich, and brook. Look up those on the internet and become familiar with the symptoms: if they break out in quarantine, you can cure them.
Try to prevent your water having highs and lows of quality: if you don't have an ATO [auto topoff] get one ASAP.
Use only ro/di water. Conditioners don't remove all the bad things from tap water.
I think the 2 things that will do you most good are a quarantine tank and a well-kept, well used logbook.