Original > Hot Tub Forum

Best online pricing for hot tub chemicals?

<< < (2/4) > >>

Waterlogger:
dichlor is expensive and there is about 3 companies who make it...cant see there being much difference in price unless its full of fillers. I use 100%, $60 -100 for 7kg

richierich:
Spa choice is 99% dichlor. I use it and find it to be a good product that sells at a reasonable price. Spadepot.com has been a reliable source for spa related purchases, mostly chems.

chem geek:
If you want to save money on spa chemicals like Dichlor, then get the same chemicals sold as pool products.  For example, while Leisure Time Spa 56 Chlorinating Granules cost $37.99 for 5 pounds so $7.60 per pound, the pool product GLB Granular Chlorine costs $24.95 for 4 pounds so $6.24 per pound.  Both of these products are 99% Dichlor.  The Spa Choice Spa Sanitizing Granules at SpaDepot referred to in earlier posts at $29.95 for 5 pounds is a good deal at $5.99 per pound.  Note that Pool Solutions Stabilized Chlorine Granules are on sale at $26.99 for 5 pounds so $5.40 per pound and for 10 pounds it is $4.70 per pound.

Of course if you were to use the Dichlor-then-bleach method then the cost would be far lower since you can get 8.25% bleach for $3.50 per gallon at Walmart.  One pound of Dichlor creates the same amount of Free Chlorine (FC) as 98 fluid ounces which costs $2.83.  If you switch to using bleach after using Dichlor to accumulate around 30 ppm Cyanuric Acid (CYA), then you'll want to lower the Total Alkalinity (TA) to around 50 ppm and use 50 ppm Borates such as from boric acid from Duda Diesel or The Chemistry Store.

Levelheadsteve:
If you only use dichlor and then shock with a high level of dichlor (is that a method?), will the CYA build up too high if you drain the tub every four months or so?  Or are there too many variables to be able to answer that?

If you use dichlor daily, is there a preferred method of shock?

chem geek:
For every 10 ppm Free Chlorine (FC) added by Dichlor it also adds 9 ppm Cyanuric Acid (CYA).  Whereas the FC gets used/consumed, the CYA remains and only slowly gets oxidized by chlorine at the rate of roughly 5 ppm per month.  So yes, using Dichlor regularly, even if you don't use it to shock, will increase the CYA level making the chlorine less and less effective over time.  This is the primary reason one needs to change the water fairly frequently and without an ozonator roughly follows the industry Water Replacement Interval (WRI).

WRI (days) = (1/9) x (Spa Size in Gallons) / (# of Person-Hours Per Day)

(Technically, the industry formula uses 1/3 but assumes roughly 20 minute soaks.)  To avoid the buildup of CYA, one can use the Dichlor-then-bleach method where one uses Dichlor until one has cumulatively added around 33 ppm FC so is at around 30 ppm CYA.  After that, switch to using unscented plain (NOT splash-less, outdoor, etc.) bleach.  About once a month use Dichlor for a day to add back some CYA.  If you use this method, then once you switch to bleach you need to have the Total Alkalinity (TA) be low at around 50 ppm and should use 50 ppm Borates for additional pH buffering.  With this method, you can usually go at least twice as long between water changes compared to the traditional formula.

If you still want to use the Dichlor-only method, then if you use bleach to shock then that will reduce the amount of CYA buildup.  However, if you are properly maintaining the chlorine level and adding the appropriate amount after every soak, then there should be no need to shock (especially with the Dichlor-then-bleach method -- with Dichlor-only towards the later part of the water replacement interval you may need to shock to make up for chlorine's ineffectiveness in the presence of high CYA).  If there is no ozonator, then the rough rule-of-thumb for the amount of oxidizer that needs to be added after a soak is that every person-hour of soaking in a hot (104ºF) tub requires 3-1/2 teaspoons of Dichlor or 3-1/2 fluid ounces of 8.25% bleach or 7 teaspoons of non-chlorine shock (43% MPS).  The MPS is only used with silver ions such as in the Nature2 system.

Navigation

[0] Message Index

[#] Next page

[*] Previous page