General Purpose Erosion Feeder

[Old Guard]

I have just drained, cleaned, plastered and refilled my "smaller" 150,000 gallon outdoor pool in preparation for reopening in May. As I dump 50 lbs of CYA and 400 lbs of Calcium Chloride into the pool just for starters, I start thinking about erosion feeders. The way I am doing it is to pour it out of bags and then brush the resulting piles out into the pool to disperse it. Then I brush it again the next day to disburse what I missed on day one and that which had regrouped over night. Would it not be better to just dump a bag per day into a largish-general-purpose erosion feeder? Must be a flaw in my theory as I cannot readily find such a "largish-general-purpose erosion feeder" on the world-wide web.

I have a 450,000 gallon pool to fill and dose in early May. I sure you can imagine how many bags of calcium will have to be schlepped and swept in that case!

 

[ajw22]

CYA is a mild acid.

Dumping CYA on a plaster pool floor can cause stains on the plaster floor depending on the color of the plaster. I don’t know if that is a concern in your commercial pool.

 

[Lake Placid]

Calcium Chloride is exothermic when added to water. I would not add any in quantity to an erosion feeder. Bad things could happen. If you have a gutter style suction system that flows back to a surge pit, you could add it in doses there so long as you have a steady strong flow of water in it during the additions. In managing pools of that size, adding calcium flake wasn’t cause for too much concern for me as it dissolved relatively quickly.

As far as CYA - dissolving it in 5 gallon buckets with warm water and then adding the mix to the pool can work, but it’s messy and time consuming. Again if you have a surge pit you can dissolve it in two ways. Tie off a heavy burlap bag filled with CYA in the pit and allow it to dissolve over time or drill loads of holes in a 5 gallon bucket with a lid, add cya to that and tie it off in a surge pit. This is much like the sock method described for residential owners here. I’m a little surprised you’re adding CYA at the same time as calcium, I‘d suggest balancing every other parameter first, then finishing with the CYA when the water is in check.

 

[Old Guard]

Thanks AJW and Lake Placid. Always learning new things here. I knew to try to get to CH targets before TA but have always treated CYA in a silo. Unfortunately, I have no surge pits or tanks in my four-pool collection. The other two are indoor pools.. No CYA.

 

[ajw22]

CYA contributes to TA levels. So adjust CYA before TA.

Read TA - Further Reading