Green water

[o2cool]

Good morning this is my first post. I was hoping you could help me with a couple of questions. We have a 55,000 gal. pool. When it turns Green with Algae; we treat it promptly put it take so long to clear. We have (2) two 36 gal.
Neptune-Benson sand filters; and use a 3 phase/5 hp StaRite pool pump. But it still take days to clear. Any help or advice you could give would be greatly appreciated. o2cool

[PoolDoc]

NOTE TO OTHER POSTERS: the OP here operates a medium sized COMMERCIAL pool, subject to pool codes and bather loads that make its operation VERY different from home pools. Please do NOT respond with advice appropriate only to home pools!

Hi Isi;

1. It's normal for pools to take multiple days to clear after an algae episode It would be possible to build a filter system that would overcome this, but the chance that an organization like yours would pay to install it . . . AND operate it . . . is slim to none.

2. The solution is very simple: do not let the pool turn green.

3. The *starting* place for you is the learning to USE and INTERPRET the K2006 test kit. The Amazon link is in my signature; get the commercial size PLUS 2 K1000 test kits.

4. The next step depends on your situation AND local code enforcement. Here are your options.
=> (a) Maintain low CYA (25 - 45 ppm) and moderate chlorine (3 - 5 ppm) 24/7 and a faithful physical cleaning program. If you have a moderate daily bather load, this will require inspecting and testing the pool 1 - 4x per day. Low end is if you have an ORP/pH controller and know how to operate it correctly . . . something NOT taught by any of the controller companies.
=> (b) Install a salt-system, and maintain the levels and cleaning per above. This will cut daily inspections to 1 - 2x per day.
=> (c) Run a high CYA (80 - 150 ppm) and high chlorine pool (7 - 20 ppm), with or without a salt system. This will reduce daily requirements to 1x per day.

BUT:

1. Only option (a) is likely to be fully compatible with your local code.

2. If Neptune-Benson is still using those junk carbon steel shaft butterfly valves, salt is out of the question. Otherwise, you'll have to check filters, pump, and heater for salt compatibility.

3. If you go this route, you'll have to depend exclusively on advice from my sites (PoolSolutions / PoolForum). Nobody else teaches how to do this. (Chlorine 'shooters' have been doing this for years, but they won't teach you. The PPG "Sustain" system is similar in structure, but they don't explain this to ANYONE.)

Otherwise, every training program; every pool inspector; and every resource will tell you this is WRONG.

Please do NOT waste our time, saying we can't check the pool every day, much less 4x per day. If that's so, your pool is going to remain screwed up. Period.

I realize this may not be your choice, but may be decided by a manager who is clueless, and can't be clued in. If that's the case, I'd recommend sending some salesmen for 'miracle' systems, like salt or ion systems, to the manager. Just make sure the manager VISIBLY takes credit for the choice to buy into whatever gizmo he gets. That way, when it fails, he won't find it easy to scapegoat you.

Good luck.