Sounds good, since they have 125 DT and about 15 sump, effective 140g sytem water, I was going to do a large PWC of right around 50 gallons, or about 35% and then monitor the levels over a week to see how it balances out. Right now the Nitrates are over 100 ppm on my Salifert kit, and too high to really tell where it's at on API, the colors at that level just blend together. For anyone who was following my thread about starting up aquarium maintenance, it's the same system. The guy doing it now isn't addressing the issue, and the guy I thought could help them isn't doing anything consistently.
On top of that, I found another customer in a Chinese restaurant with a 125 long FOWLR, super dirty, no protein skimmer, not enough LR, no CUC, but has had no fish die in years. He's got 3 Sergeant Majors, a dog-faced puffer, and a yellow tang. One of the SMs has swollen gills to the point where it looks like something fleshy is hanging out of his gills at the bottom. Tried to get a pic to post but no luck. Nitrates off the scale on that one too.
He's also got a 225 that he had Discus in but they all died, and I'm going to set that one up as a cichlid tank with PFS substrate.
His Uncle used to take care of the tanks, and when he moved, they went downhill apparently. How the SW has even survived without a skimmer I have no idea.