You are right, I'm making an automatic water change, but what about PH, from the tape usually I have 8?QUOTE=jjb;7105104]Hith is very hard to treat especially when they are that size ,,, Ive also noticed it is common in these fish well some ,,, I've gown out several 4-5+ year old Pbass and some get it and some didn't ,,,, tems in my opinion seem to not get as easy as ant others especially ocells,,, everything I've read it's seems to always relate to water quality and water changes and Iam so jealous of your 600 gallon Ive had a 330 for years ,,, Iam still spacing out where my 11footer is going when I get it and you would think with a 600 plus tank you could get away with less water changes but I think it's relative ... I currently have 3 tems I kiolbera...and two Os so yea too much for 330 but once a week I have an auto changer I do 125 gallons and yes my water bill is high as heck in Texas but no hith and my last crew had zero as well ,,,I also had a large FW stingray for a year but he hemoraged his nose and died but I knew guy who did hardly any water changes in a 250 and had a tem at 28" and was super healthy looking fed him hot dogs and crap ,,, so you can never tell ,,, but yes after 25 years of raising Pbass O's seem get hith a lot easier then others ,,,I've also noticed it seems the lateral line gets more pronounced right before hith sets in and again so hard to treat once they get it if it's even worth it they can live out a long life with it as well ,, good luck on your new Batch and looks like Uve got a huge wet dry under it as well ,,, I run a huge wet dry with pads to catch stuff before the bio balls with a monster 40uv w/ wiper aerator in the sump and in the tank from a large air pump housed in the garage and that's it ,,, post pics of ur new fish !��[/QUOTE]