Is it possible to add too much PR-10,000 at one time? And if so, what happens? What are the consequences?
Yes, it is possible to overdose PR-10,000, and we do not recommend it. Too much PR-10,000 relative to the phosphate levels in the pool will not leave behind a residual, but it is wasteful. When there are no more phosphates present, PR-10,000 will react with the next best things, whatever they may be.
The consequences of overdosing PR-10,000 are not toxic, but they can be a headache. Here are some:
- You may need to close the pool down for an extended period of time, up to a four or five days, due to prolonged cloudiness.
- You may have excessive fallout that can build up too much pressure in your filters (especially DE) which could cause damage. We have seen DE grids get crushed before. As mentioned in our How to use PR-10,000 article, always time your heavy PR treatments a day or so before a DE filter clean and media change.
Best Practices for purging with PR-10,000
We have learned over the years that PR-10,000 precipitate clouding can take much longer to clear in pools with heavy bather loads. This, we believe, is due to non-living organics in the water. Non-living organics float or stay suspended, and PR-10,000 fallout can stick to these oils, holding them in suspension longer. PR dust tries to fall, while oils rise.
We know there's something to this because on the densely-loaded commercial pools we have purged, when we purge with CV-600 or CV-700 enzymes ahead of time (or at the same time), the cloudiness clears much faster. Usually within 48 hours. If not, it can be several days.
Worst case scenario
If you do overdose PR-10,000 accidentally–and it happens often–just make sure people do not get into the pool until it is cleared up. This is not so much a toxicity thing as it is a visibility and safety thing. Cloudy water can hide the bottom of the pool, and that becomes a drowning risk.
But in the worst-case scenario, when the water eventually clears, you will have some beautiful water and better chlorine efficiency. It's just not a cost-effective or practical way to do it.