I have virtually no CYA in the water; can't really test less than 30ppm. I use a tri-chlor feeder all season. Last year my pool builder told me to never add CYA because I use tri-chlor. By the time I closed the pool, I think i might have had 30ppm in the water, then I lowered the level for the winter. At this time it would appear I have no CYA in my water and I can't get Chlorine to stay in the water. Is it safe to add stabilizer to get my CYA up to 30 and use tri-chlor all summer?