Opening Algae Problem

[FormerBromineUser]

Nope... PoolDoc's father passed recently and he is taking a hiatus from the forum and will hopefully be back soon. I know he was working on a new closing system but in the meantime you could read some RECENT (2013) posts about closing. So glad you got the K2006 and are loving BBB! Let us know if you need anything!

[PoolDoc]

Actually, yes . . . with the understanding that it's a TRIAL. I've seen good results in my local use and testing, but this approach is new to the PoolForum.

Basically, it involves the following steps:

1. Clearing your pool from all existing algae with high chlorine. This can be done with the pool partially covered (or fully covered, if you have a mesh cover).


2. [OPTIONAL] Raise borates to 60 ppm. On your pool, this means 25 boxes of borax and about 8 gallons of muriatic acid. Note that this is a PERMANENT addition. The borate is removed only by draining (or leaking) water from your pool. Evaporation has no effect. So, if you raise borates this year, you'll only need to top-off in coming years, unless you drain and refill the pool.

Borates > 60 ppm are a weak algae and bacterial inhibitor. It make a noticeable, but not huge, difference. Other effects include "sparkly water" (changes the refraction index a bit) and more "comfortable water" (somewhat like the effects of adding salt).


3. Test and lower phosphates (PO4) to 100 ppb OR LESS.

This is a BIG change here. I've counseled against phosphate removers, because they were overpriced and usually ineffective. It turns out the reason is that phosphate removers are useful ONLY if you lower levels to 200 ppb OR less. If you lower PO4 from 4,000 ppb to 1,000 ppb and stop . . . you've totally wasted your money.

During the pool season, it can be difficult to maintain low PO4. Refill water from the hose often contains 3,000 or even 5,000 ppb PO4. But this is not an problem once the pool is closed.

Also, it turns out that there is a concentrated phosphate remover (Orenda PR-10000) that is reasonably economical IF you purchase it carefully. One quart can be purchased for $55 delivered, and will remove up to 3,000 ppm from your pool.

For your pool you need at least 3 quarts of PR-10000 (even if you don't use them all!) and a Taylor K-1106 testkit.

PLUS, you need 2 weeks. For reasons I don't fully understand, the TOTAL amount of PO4 in a pool typically seems to be higher than what appears in the water when you first test. I suspect that -- initially -- the PO4 in the fill water 'coat' all surfaces, including pipes, filter sand, liner, etc. (This coating effect helps prevent metal corrosion, which is the reason for adding the PO4 in the first place.) Once you lower the PO4 in the pool water, the PO4 attached to all pool surfaces re-enter the water . . . and have to be removed.

So, to remove the PO4, you have to lower the levels a LOT (> 500 ppb), and then keep adding smaller doses of remover, till levels drop below 100 ppb and REMAIN there. This takes time.

The effects of this treatment CAN be permanent, but ONLY if you continue to add small doses of phosphate remover EVERY SINGLE time you add fill water. (Rain water may, or may not, add PO4. The data I have is conflicting: you'll need to test and see.)

BENEFITS: very low levels of PO4 (< 100 ppb OR 0.1 ppm) slow algae growth greatly, and bacterial growth somewhat. This makes it MUCH easier for biocides (like polyquat) or sanitizers (like chlorine) to kill the algae or bacteria. Combined with low water temps, low PO4 levels should result in greatly reduced problems with opening.


4. Test the water 'balance' factors with the K2006. Adjust pH and TA as needed to establish a slightly negative saturation index, to avoid problems with scaling.


5. ONCE
=> pool water temperature is below 70 degrees,
=> water is completely clear,
=> pool is completely algae free,
=> saturation index is correct, and
=> PO4 levels are below 100 ppb
THEN cover the pool fully.


NOTE: Winterization can be paused at this point, and the covered pool can be operating in this state for weeks, if needed. Keep chlorine levels in the 5 - 10% of CYA while doing so. Monitor PO4 levels, however.


6. [OPTIONAL, but recommended] Put filter on bypass (or remove cartridge or DE powder) and add 10 ppm of polyquat (about 2 quarts on your pool) to your pool water. Circulate for 2 hours before finally closing pool.


7. Shut down system, and winterize pool piping and equipment.


8. Inspect under pool cover monthly, during months when pool is NOT frozen, using a water proof flashlight. At the first sign of slime or cloudiness, dilute polyquat in water (1 gallon per quart) and add to pool at 4 corners.


9. Open pool before water temperature exceeds 70 degrees. Test pool water before opening. IMMEDIATELY add a chlorine dose equal to 20% of the CYA level.


. . . . anyhow, that's the plan.

I'm going to be offering a limited number of 'kits' containing (3) quarts of PR-10000, (1) quart of polyquat, a K-1106, a calibrated pool thermometer and a registration and instruction package, so users (and I) can track results online. It looks like I'll offer this for about $225 delivered to 48 states.

The package will be available ONLY to pool users with a K2006, who are willing to participate in the trial. I will create a special forum section for discussiing these results, and set up automatied reminders (text / email) of winterization milestones.