Best Source For Bulk Mps

[The Pup]

I use Bromine as a spa sanitizer because, for many years, I was often called away for work during the week and I found the benefits and cost to be more than worthwhile (typically $3-6 per month). For many decades I have purchased spa chemicals in bulk to save money and I am looking for a cost-effective source for MPS shock.

I have found the amount of Potassium Monopersulfate (MPS) in different spa-shock product ranges from 28%-to-43%...this is a factor for cost because I assume I will use less 43% MPS than a 28% MPS product. I can buy DuPont Oxone (the active ingredient) in bulk but I prefer a Ph nutral buffered product.

Note: This is an exercise to determine the lowest consumer product unitized bulk cost...which may seem slightly ridiculous when faced with storing 50lbs of MPS when rarely using more than 3-4oz per week.

So far, I have found the following "best deals" (your shipping costs and local taxes may be a mitigating factor):

Leslie Pools Fresh 'n Clear (38% MPS) at 40lbs for $109.99 (free shipping).

Effective cost: 5.818oz of product per $ or 2.21084oz of MPS per $.

Doheny's Water Warehouse Oxi-Shock (43% MPS [per the MSDS]...although their sales' department states 45%) at 50lbs for $144.99 (free shipping with $9.99 handling fee).

Effective cost: 5.162oz of product per $ or 2.2196oz of MPS per $.

Sears Water Warehouse Oxi-Shock (43% MPS) at 12-1lbs for 29.99 (+ shipping...$9.00 nominal 48 states [will not ship to CA]).

Effective cost: 4.924oz of product per $ or 2.1173oz of MPS per $.

In comparison, my local spa shop sells Leisure Time "Renew" 32% MPS at 2.2lbs for $21.99 (online you can find it for 14.99 with free shipping).

Effective cost: 1.6oz of product per $ or 0.512oz of MPS per $.

Perhaps the lower percentage MPS products offer buffer or assimilation advantages, but in my simple mind...higher MPS percentages provide more of the active ingredient I am shopping for.

Please post if you are aware of better/cheaper MPS shock bulk alternatives (perhaps placing Chlorine-based shock cost comparisons on hold for this discussion).