AA treatment this fall or wait till next spring?

[kmdigital]

My pool has bad iron staining in some spots and a general dirty looking iron coating on the vertical fiberglass walls, especially the south shaded side. I just bought the house in July, and the previous owner opened this spring with straight well water at 5 PPM iron, which is where the iron comes from. Previous years he opened with soft water, but was cheap this spring, and regretted it afterwards, as he said he didn't have the staining previously. And yes, vitamin C tablets take them right off.

I need to do a major drain on the pool due to high CYA (130) next spring anyway, and given that I can get iron free and relatively low TA water pumping from the lake, I'm inclined to change all the water totally eliminate the iron and removing the need to use a sequestrant going forward. Additionally, because my well water has very high TA (450 hard, 550 softened), I have to use another water source or live with very high TA levels, as reducing it to ~100 with MA wouldn't be practical.

The question is, should I do the AA treatment this fall in preparation for a full drain next spring? My concern is that the iron might redeposit over the winter while the pool is closed due to sequestrant degradation. Also, if I do it this fall, I will need to mess around for a couple of weeks slowly raising the FC and PH levels up up again just before I close it, which seems like a lot of work for water that will be dumped next spring.

The more I think about it, the more I think it might better to wait till spring to do the AA treatment. The primary drawback will be working with colder water which means it will take longer for the AA to work. However, I'm thinking that the fact that once the stains are gone, I can just dump all the water and replace it, without worrying about sequestrants and slowly raising PH and FC will make it a lot easier and better. If I get the stains out, and then dump and replace the water, I can just immediately SLAM the new water, add CYA and essentially be done with it.

What say the experts?

 

[Swampwoman]

Not an expert by any stretch but since I have a few historic "foreclosure" iron stains that even AA doesn't adequately handle, I'd personally clear the staining while its fresh and then make sure I'm dosed up full on sequestrate when you close. But that may be a knee-jerk response on my part

 

[257WbyMag]

What part of the country are you in? If you are in an area where you can go without having to close your pool, you may benefit by doing the treatment then. Because cold weather decreases your chances of dealing with a huge algae bloom when letting your FC go to zero (required for an ascorbic acid treatment), the off-season may be the best time to hit it.

 

[kmdigital]

What part of the country are you in? If you are in an area where you can go without having to close your pool, you may benefit by doing the treatment then. Because cold weather decreases your chances of dealing with a huge algae bloom when letting your FC go to zero (required for an ascorbic acid treatment), the off-season may be the best time to hit it.

I'm in northern Indiana, so it get's quite cold in the winter. Are you saying I don't necessarily need to bring the FC back up after the AA treatment, and can just close the pool since it will drop to zero over the winter anyway?

 

[kmdigital]

Any specific suggestions and why I should do it in the fall or spring?

 

[BoDarville]

Given that you will likely close the pool for the winter (being in N Indiana) and that you plan on replacing the water in the spring, I would do the AA treatment in the spring once the water temperature is in the range of 50-60 °F. At these temps, the change of an algae bloom is significantly reduced. When the stains have lifted, then immediately drain the water which will take the metals with it. Once you refill, test your water and adjust the chemistry as needed. If you use lake water, you will likely need to SLAM.

 

[kmdigital]

Thanks, that's what I wanted to know. I will definitely close the pool as soon as it cools down to < 60 water temp, but given that it's 95 degrees today, it may be a while yet. Strange weather we're having and it was much cooler in July than most of Aug and definitely now.

Originally, I planned to do the AA treatment this fall when the water cooled down, but then I got to thinking about it, and thought it might actually be better to do it next spring. I want to fill in the spring instead of the fall as the algae in the lake water will be dead, or at least dormant, which it definitely isn't now. Plus with snow and ice melt, the water will be cleaner with no boat traffic and with lower CH and TA content. With my very high TA well water I can very easily raise it by adding some well water, so the lower the better starting out.