Polyquat algicide

With the heat wave happening and the sun blazing down on your pool, fighting algae and maintaining sanitizer levels can be a challenge. Here are some tips to help.
#1 Sanitizer: Doesn't matter if you're using chlorine or biguanide, keeping sanitizer and oxidizer levels where they need to be is by far the most important thing in keeping algae at bay. Chlorine pools are more vulnerable to hot weather and the sun because the gaseous nature of how chlorine works. Chlorine pools (salt water too) require cyanuric acid to stabilize the chlorine. Non-stabilized chlorine has a half life of about 35 minutes in the sun. You can add chlorine all day and it will burn off fast if cyanuric acid is not present. Ideal cyanuric acid levels are debated widely, in my experience 20-30ppm works very well. If you're using trichlor tablets or dichlor powder, no worries, cyanuric acid is built in. However, it can be helpful to give an initial dose of cyanuric acid on a fresh fill as it will take time for trichlor or dichlor to raise cyanuric acid levels. If you're using cal hypo tabs or powder, you will need to add it manually. Don't over dose your pool on cyanuric acid though, over-stabilization will reduce the effectiveness of chlorine and leave your pool open to algae. For biguanide pools, oxidizer is key. Keeping peroxide levels at the high range will help tremendously. I like 150-200 ppm for peroxide.
#2 Circulation: Getting sanitizer in the water is one thing, circulating throughout the water is another. Poor circulation can lead to dead spots where algae blooms. Having a properly sized pump will help with this. If you're using a cheap vinyl pool, I highly recommend upgrading the pump. The stock pumps are trash. Return jets should be angled down at 45 degrees and all of them turned left or right, all in the same direction. Circulate counter clockwise on the northern hemisphere and clockwise on the southern. Circulation is also key if you're using a floater with chlorine tabs. Chlorine tabs are erosion tablets, not dissolving tablets. They require water flow over them to erode them into the water. If your pool has poor circulation (cheap vinyl pools,) I recommend 1 inch tabs over 3 inch. One inch tabs have much more surface area to chlorine ratio and will disperse into the water better.
#3 Filtration: Proper filtration is key in filtering out debri/contaminants and also has a large effect on circulation. A dirty filter will slow your flow rate and slow circulation. Keep your filter clean! I personally prefer sand filters because of how easy they are. You can even achieve cartridge filter quality if you use a glass based sand. for sand filters using 300+ pounds of sand, I recommend a layer of pea gravel as well. Using a chemical degreaser on your sand once or twice a season is usually enough. For biguanide pools, I recommend changing your sand every season, as biguanide filters out more contaminants rather than gas them away like chlorine. For cartridge filters, use a chemical degreaser on them when your pressure climbs 5-10 PSI above what it runs on a clean filter. A light acid wash after can make it extra clean. NEVER acid wash any type of filter before chemically degreasing it. Acid will solidify the oils and can ruin a filter cartridge, or lead to channeling in a sand filter. I'm not gonna talk about D.E. filters much as they're kinda being phased out. While D.E. does provide the best filtration, is also a known carcinogen and should be handled with care. It's like getting fiber glass on your skin. I recommend covering your skin, using gloves, and a face mask when handling D.E.
#4 Algicides: Algicides, while not always necessary, can be a helpful addition to pools to keep algae at bay. Polyquat algicides are a good preventative measure and work in all types of pools. Copper based algicides are also effective at preventing algae, and are the most effective at killing algae if you already have a bloom. And don't worry about it adding copper to your water, copper based algicides are chelated to prevent the interaction of copper with other chems. NEVER use a copper algicide in a biguanide pool, polyquat only.
#5 Shocking: I cannot stress enough how important it is to shock your pool every week. Chlorine combines with contaminants to create chloramines (combined chlorine.) Combined chlorine is not an effective sanitizer, makes your pool stink like bleach, and causes skin/eye irritation. Shocking breaks combined chlorine apart to gas away contaminants. Shocking with chlorine requires about 1lb per 10k gallons, or roughly 10x the combined chlorine reading. Using a quality shock will help too. Those cheap 7 in 1 shocks like HTH I've seen cause more problems than help. For biguanide pools, it's all about the oxidizer (hydrogen peroxide.) Don't be afraid to over dose it some with peroxide, especially after a heavy swimmer load like a party or something. It won't hurt anyone and it's critical to filtration and sanitation.
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Hope this helps some people during this heat wave. Hit me up for more specific questions, if I made a mistake, or you just want more info. Just keep swimming peeps

I purchased a home in March and opened the pool mid April. It was a bit of a mess as it was left to sit from early July ‘19. On opening, the water was black with algae, but it is now finally blue!
I did several large shocks (FC 30 - 35 ppm) + Green Treat algicide to get rid of the black water - PH was 6.6 - 7.0 when I did this. I think this caused some metal to leech into the pool (likely copper), causing staining on the stairs and lining. I removed staining by dropping the chlorine and treating the pool with citric acid, CuLator and polyquat 60 algicide. Kept FC down for 2 weeks while the CuLator did its thing, and kept algae at bay with ployquat.
To get the chem safe enough to swim, I have shocked (FC 12-15) every evening for the past 7 days. Each morning the chem is about the same, FC 0.2 ppm and CC 0.8 - 1.2 ppm.
I am mostly using 65% Cal-hypo to shock but have started using 10% sodium hypo in the last couple of days. I am measuring chem using Taylor 2006 FAS-DPD and Leslie’s.
Pool: 32,000 gal, vinyl liner, DE filter, Tri-Chlor in automatic chlorinator
Chem:
FC: 0.2 ppm CC: 1 ppm PH: 7.4 TA: 105 ppm CH: 120 ppm CYA: 37 ppm (now, but was much lower 2 weeks ago) Phosphates: approx 3000 ppb
• Since the pool has definitely become more blue over the last 7 days, do I just keep going with the shocking? • Do I add more algicide to help FC remove any remaining algae? • Do I have to remove phosphates? - expensive • Am I just oxidising the algicide when shocking, thus increasing my FC demand?