I'm the guy with high CYA who has converted to the BBB pool method. For the last two weeks I have maintained FC above 20ppm. I have used PolyQuat 60 at the "algae present" levels. Now I have what looks like algae at the seams on the bottom of the liner. Some accumulation away from the seams but in the vivinity of the seams. I have excellent circulation from the pump. I'll describe it as best I can.
You can vacuum it out but it starts to slowly gather the next day at the seams. You can just pass a brush over it softly and it disappears. The color is a very "slight" beigey/brown. It forms in a circular pattern (quarter size away from the seam or in a straight line within the seam. I can use a sock in the skimmer and it will only slightly discolor it in a vacuuming. The discoloration just looks slightly dirty.
If it is algae I question if it is dead or alive at the rates of FC I have maintained plus using the PQ60 first at the "algae present dosage" then following up every 4-5 days with the maintenance dosage.
1- Sound like an algae?
2- Any ideas on ID from you pros?
3- Dead or alive (best guess) - how do you tell the difference?
4- Recommend a different approach?
My FC and TC are only one drop apart - almost no CC's above 20ppm)
My pH is about 7.7
My alkalinity is 140
My CYA is 117+
Hardness - 210
Copper - 0.0
Iron - 0.0
Many thanks - it just hasn't been a car free year for me........... Jim
P.S. My water has been crystal clear (blue diamonds) since I opened it this year!