Tub fill with well water questions

[Drdadr]

We got a Bullfrog A8 last year and we included the ozone unit. We use the frog@ease cartridge system. First time we filled it with straight well water from the outside spigot, with a hose-end filter. Seemed like it took several weeks to get the chemistry right with metal remover, phosphate remover, really low free chlorine etc.

Our well water has 1-3 ppm iron but has a lot of sulfates and both iron and sulfate reducing bacteria which caused a lot of rotten egg smell in the house water. As a result we had an IC storm ozone unit installed before our water softener. This really helped.

The last time I drained and filled the tub I used half straight well water and half soft water from an inside faucet which I ran out the window with a hose. This seemed to work well.

I was thinking of having the spigot by the hot tub changed so it came off the treated water lines and not straight from the well. However I’ve read you are not supposed to fill totally with soft water. Is this true? I’m also wondering if I could have the hot tub spigot come from the IC storm (iron/sulfate treated water) before it goes through the softener, at least to eliminate some of those problems. Thoughts?

 

[Mdragger88]

Filling an acrylic or fiberglass tub with completely softened water is fine. That reccomendation is generally for plaster pools which need some ch & are also quite large putting a strain on a softener system.
My fill water has a ch of 25 & I don’t add any calcium unless foaming becomes an issue.
You want as few metals in your tub water as possible so using filtered water is ideal.

 

[Methuselah]

Your use of the frog system can lead one to the belief you don't need to add chlorine on a regular basis. If you are using dichlor, or "shock", you'll be adding CYA too, which can tie up your free chlorine...

I'd suggest reading the sticky pinned to the top of this forum. It will help explain the above relationship and "put you on the path".

 

[JoyfulNoise]

You can fill the tub with softened treated water. All I would suggest is finding a source of calcium hardness increaser and use that to add back 50-100ppm CH. It shouldn’t take much at all with your tub volume so a big container will last a long time. You do want some CH in a tub to avoid foaming.

As for your method of sanitation, that’s ultimately your choice, but the frog@ease system is not your friend. It’s a lousy way to chlorinate a tub and it’s ridiculously expensive. Like others have pointed to, you should look at the Sticky threads at the top of this subforum for using chlorine or bromine in your tub.

Finally, if you haven’t already, you should do an Ahhsome purge of your hot tub even if you bought it new. Biofilms are prevalent in hot tubs (even new ones) and they represent a constant source of sanitizer demand. A fully purged and cleaned hot tub is much easier to balance and manage.

 

[Methuselah]

A fully purged and cleaned hot tub is much easier to balance and manage.

+1

 

[5tan]

Step 3 on page 14 of your Bullfrog A-series manual states "Never fill the spa with soft water unless an appropriate mineral supplement is immediately added"

Now you can opine about manufacturers trying to convince you to buy their products, but you should also consider if their statement has any academic or scientific merit. So you ask yourself, why would they write this in their manual, and what do they mean by mineral supplement? I know that the process of softening water replaces calcium and magnesium with sodium, probably with near zero impact on pH, and I know that magnesium is of little to no concern for maintaining a hot tub and cannot be directly measured anyway, so the primary issue must be related to the lack of calcium. Therefore, I conclude that Bullfrog has a concern regarding their equipment and extremely low calcium level, and their recommended mineral supplement at the very least, will be adding calcium to the water. Another possibility for their concern is that naturally soft water typically has a low pH, which would be corrosive to metallic parts. However, water softened by ion exchange does not have low pH, so the method by which the water is softened should be a consideration. It would be interesting to see what the contents of the "mineral supplement" are, which should then tell you what specific minerals they are concerned about, and then you can go figure out why lack of those minerals might be a concern.

So long as you measure your input fill water and adjust for the most potentially damaging factor upfront, you should not have any problems. For example, if your fill pH is low, you want to adjust pH slowly as you fill up. If your fill pH is high, then you want to introduce very small amounts of acid gradually as you fill up. You should also wait 12-24 hours before adjusting any other parameters such that you don't cause balancing agents to precipitate out and make your new water cloudy. Also note that when water has 0 CYA, chlorine is much more effective at lower pH levels, so if you want to ensure maximum pathogen kill, lower your pH to 7.2 prior to adding liquid chlorine. This math goes out the window once you add solid/granular/stabilized chlorine (due to presence of CYA).

And definitely purge with Ahhsome + superchlorinated water, scrub everything with a Lysol blue sponge including the backs of the JetPaks, and ditch the Frog system. Liquid 10% pool chlorine is cheap and easy to measure out (I use a glass pasta jar with mL markings, easy to add 50/100/150/200mL depending on bather load).

I also use both the authentic Nature2 stick and the Chinese knockoff Nature2 stick, putting both behind my 2 filters. Hard to measure if they do anything versus not having them, but science says the copper and silver should help inhibit biological growth, and my regime keeps the water clean and easily manageable for at least 6 months of extremely heavy use, third year of A7 ownership now.

 

[JoyfulNoise]

The recommended mineralization requirements are not based on any rational criteria for the materials involved. They are basically “boiler plate” language that was co-opted from the water boiler and cooling tower industries where a certain level of mineral hardness is need to ensure that steam generating pipes and metallic surfaces are coated with a layer of carbonate scale to protect the metal surfaces from erosion. It’s an apples-to-oranges transplant of language so that warranty requirements can be quantified. It has nothing to do with the physical or chemical reality of water moving through a heater. Most of the components, including the shell, of the hot tub are polymer materials that have no need for any calcium or mineral exposure. The only reason to add mineral hardness to the water is to keep the water from getting foamy which can easily be achieved at a level of CH far lower than what most warranty requirements will dictate.

As for copper and silver ions, they have very little use. Copper ions act mostly as an algaecide in water and have very little disinfection activity against disease-causing pathogens (viruses or bacteria). Silver ions are only considered to be a sanitizer and have fast enough kill times when the water temperature is above 100F and there is a supplemental oxidizer present like MPS. The CDC and EPA only consider silver to be an allowable tub sanitizer when it’s silver ions + MPS AND the water is held at or above 100F. Chlorine, by and large, has much faster pathogen kill times than silver even when CYA is present to moderate its strength.