Does a 200 ppm CYA level invite Black Algae?
Seems like I can't keep a high enough chlorine level with this high of a CYA. Black Algae is mostly on the walls with some now spreading down the deep-end walls and a just little on the bottom.
To find the 200 ppm CYA value, I used the Pentair Rainbow Cyanuric Acid Turbidity Test Kit.
Since the water is off the chart of the test kit, I used the dilution method by using half pool water and half tap water. I got a reading of 100 so multiplying it by 2 gives me 200 ppm CYA.
The TF-100 test kit is on order. What other readings are important. With the Taylor OTO Deluxe Test Kit, the Total Chlorine is currently ~5 ppm. The water is clear. pH is around 7.2. Haven't measured Total Alkalinity lately.
We recently bought the house and now that we've had 1 year of pool use (first-time pool owner) I'm not too experienced in pool maintenance. So for the past year, I have been using floating chlorine tablets and shock (Cal-Hypo 73%) but I'm switching to liquid bleach/chlorine with the new pool season. Been reading the TFP site and got great ideas now. CYA was high to start with when we moved in and I just kept adding to the high level not knowing much about how CYA works with tablets and Cal-Hypo shock.
In brushing the BA spots on the sides, I've been inconsistently doing it since last summer. That's when the little amount we had inherited started slowly spreading. I never saw much of a change last summer when I started brushing so I lost my will to kill it. Looking back at Leslie's Pool Water Tests, CYA has always been high. Usually 100+ each time. My own readings with the Pentair CYA tester shows the same.
I read though the Black Algae article here on TFP and some of the other forum posts.
A rough plan comes to mind: lower CYA by draining half of the ~18,000 gallon pool and while the water level is lower, I will try scrubbing with stainless steel brush which should be easier than when it's full. Possibly using bamboo skewers, too. I am also thinking of carefully pressure washing (1800 PSI unit) the BA spots then applying bleach/chlorine with a garden sprayer on the exposed spots. Maybe doing that a couple/three times? (pressure wash, brush, spray, repeat) before refilling. Maybe rubbing a chlorine tablet over spots too?
So, I figure that draining half the pool and refilling gives me the chance to attack the BA and lowers the CYA level.
Again, this is the rough plan of mine. Advice?
I haven't done anything yet other than ordering some items: TF-100 kit and submersible pump. Still need to find liquid bleach/chlorine here in Anaheim. Maybe it is at Home Depot? Will check soon.
Thanks in advance for any comments or help--you guys ROCK!
Seems like I can't keep a high enough chlorine level with this high of a CYA. Black Algae is mostly on the walls with some now spreading down the deep-end walls and a just little on the bottom.
To find the 200 ppm CYA value, I used the Pentair Rainbow Cyanuric Acid Turbidity Test Kit.
Since the water is off the chart of the test kit, I used the dilution method by using half pool water and half tap water. I got a reading of 100 so multiplying it by 2 gives me 200 ppm CYA.
The TF-100 test kit is on order. What other readings are important. With the Taylor OTO Deluxe Test Kit, the Total Chlorine is currently ~5 ppm. The water is clear. pH is around 7.2. Haven't measured Total Alkalinity lately.
We recently bought the house and now that we've had 1 year of pool use (first-time pool owner) I'm not too experienced in pool maintenance. So for the past year, I have been using floating chlorine tablets and shock (Cal-Hypo 73%) but I'm switching to liquid bleach/chlorine with the new pool season. Been reading the TFP site and got great ideas now. CYA was high to start with when we moved in and I just kept adding to the high level not knowing much about how CYA works with tablets and Cal-Hypo shock.
In brushing the BA spots on the sides, I've been inconsistently doing it since last summer. That's when the little amount we had inherited started slowly spreading. I never saw much of a change last summer when I started brushing so I lost my will to kill it. Looking back at Leslie's Pool Water Tests, CYA has always been high. Usually 100+ each time. My own readings with the Pentair CYA tester shows the same.
I read though the Black Algae article here on TFP and some of the other forum posts.
A rough plan comes to mind: lower CYA by draining half of the ~18,000 gallon pool and while the water level is lower, I will try scrubbing with stainless steel brush which should be easier than when it's full. Possibly using bamboo skewers, too. I am also thinking of carefully pressure washing (1800 PSI unit) the BA spots then applying bleach/chlorine with a garden sprayer on the exposed spots. Maybe doing that a couple/three times? (pressure wash, brush, spray, repeat) before refilling. Maybe rubbing a chlorine tablet over spots too?
So, I figure that draining half the pool and refilling gives me the chance to attack the BA and lowers the CYA level.
Again, this is the rough plan of mine. Advice?
I haven't done anything yet other than ordering some items: TF-100 kit and submersible pump. Still need to find liquid bleach/chlorine here in Anaheim. Maybe it is at Home Depot? Will check soon.
Thanks in advance for any comments or help--you guys ROCK!
