Help me direct my jets - black algae

[IkeRay]

I've been getting black algae in the corner of my pool for a while now. it started in '08 when I left on my honeymoon for 2 weeks, returned and the algae had set in. I poured bleach in that area and left the pump off over night, having used a metal brush prior to bleach to "pop open the cells". it seemed to have worked but they came back (same corner), and slowly started to spread. went a step further and poured cal-hypo (65%) all over the areas of affect (stairs, that corner, and some further out) and again brushed first left pool off for 12-18 hours, seemed to have worked again until a couple months passed and it was back in that corner. I'm sure its because I get poor circulation back there so firstly I need help directing jets for perfect flow of water.

I have attached a picture of my pool, blue dots represent jets, blue arrow is direction previous owner/pool guy directed them, yellow is my pool light, purple is my quick disconnect for APC, red are suction lines (main drain + skimmer), and the big black heap in the top right corner is the black algae colony origin.

I will be adding borates as my pool vendor (runs servic company, I trust him as he uses Taylor kit for testing and respects BBB method) suggested it to help fight off the black algae, he had a friend with a similar problem that was resolved by adding 50ppm borates.

 

[frustratedpoolmom]

Seems like that direction should work. The one closest to the corner - can that be directed any closer to the affected corner? Keep brushing - they are especially resistant as you know and the key to killing them (but also the key to prevention) is weekly if not daily brushing - even if you don't see them.... especially if that is a problem area - I'd be brushing often in that area even if they appear to be gone.

 

[IkeRay]

Seems like that direction should work. The one closest to the corner - can that be directed any closer to the affected corner? Keep brushing - they are especially resistant as you know and the key to killing them (but also the key to prevention) is weekly if not daily brushing - even if you don't see them.... especially if that is a problem area - I'd be brushing often in that area even if they appear to be gone.

the 3 right most returns are turned as far as they can in respective directions.

 

[lborne]

I'm not 100% sure, but I thought you want to have all the jets so that they swirl the water in the same direction. If so, then the leftmost jet is going the wrong way.

Also, the one closest to the algae can be relaced with a nozzle that has the opening to the side to allow it to shoot into the corner.

 

[Beez]

Have you tried using ping pong balls to identify circulation patterns? I did this past weekend, and was somewhat surprised with the results. Just put a half dozen or so balls in and watch the circulation pattern as you adjust the returns.

TIP: Put a couple of small punctures in the balls so that they partially fill with water. They still float, but sit lower in the water so they are less affected by wind.

 

[257WbyMag]

Ike,

If you would, post your current test numbers in this thread so that we can see them.

Thanks!

 

[JasonLion]

I recommend testing your circulation with a dye test and seeing what happens. You can do this using one or two small bottles of food coloring (baking isle), preferably a very dark color, transferred to a squeeze bottle. Spray the dye in near a return and then watch it as it goes around the pool to see where there are problems. Adjust your returns and repeat until things are looking good. The ping pong balls are reusable, but the dye gives you a more detailed picture of what is happening.

lborne's suggestion of changing your return fitting for one that can be aimed directly into the corner is a good one.

 

[zea3]

You can also try dropping a good size dollop of food coloring in that corner while the pump is running and watch how it dissipates. Do you get equal pressure from all the returns? What hp is your pump? Perhaps you could also try getting a pool fountain that attaches to a return and aim it at that corner? I don't know, just throwing a few ideas out there.