Will to start id get red of the bio balls if you have them in the filter

more snails at least 50 of deferent types iv got over a 100 in my 55

haven't had a 6 line but i thank Thea eat just pods if i remember right
so Thea need a will established tank

And you more thin likely need to upgrade your skimmer

And take a good look at your water sours if not RODI