Initial Biofilm Removal

I have a well system that produces very good water. We are just switching over from the BLEACH! system we have been using to CL02. I have a 2500 gallon tank as well as all the lines that serve the house and the rest of the property.

I can tell it’s time to disinfect because the biofilm starts to show up in the shower heads etc. I have not disinfected in a while because I really hate using Sodium Hypochlorite (bleach) because it’s so toxic.

At what PPM would all of you recommend for the initial shock to clean out all that biofilm. Would 25 ppm (approx 1 tablet per gallon) be strong enough to initially flush it all out.

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Hi there,

Shock treatment ranges from 5 to 25 PPM. But if you are already seeing biofilm formation in other locations such as shower heads, I would recommend starting with 25 PPM. This may need multiple applications in the first few weeks to fully clear out all the algae depending on how much buildup there has been.
Here is some further information on treating well water on an ongoing basis, as a healthier alternative to bleach:
The range for water sanitization (for human consumption) is 1 to 3 PPM, and up to 5 PPM if there is a known contaminant. The challenging part is figuring out the amount of standing water in your well… and we’re here to walk you through this process.

Do you know the depth and diameter of your well? These are the measurements needed to calculate the volume of standing water that will need treatment.

– In a well with a 6-inch diameter, each foot of standing water is approximately 1.5 gallons of water per foot.

– In a well with a 10-inch diameter, each foot of standing water is approximately 4 gallons of water per foot.

(Depth of well – Distance down at which water level begins) x 1.5 = Volume of Standing Water

(Replace 1.5 with 4 if your well has a 10-inch diameter)

Next, we want to plug this number into the Safrax Calculator:

Safrax Calculator

Using the US Gallons tab at the top, under the “What do you want to calculate?” drop down menu, select “Amount of Tablets/Gr”.

Plug in your answer under “Qty of Gallons” and try 3 under “Amount of PPM”. The number generated under “Amount of Tablets/Gr” in the last box will be the approximate number of tablets you want to aim for.

Play around with the numbers! Remember that we are working with an approximate volume of water and aiming for a PPM range between 1 to 3 PPM (up to 5 PPM if there is any known or suspected contamination in the area). Try calculating with 2 PPM, or up to 5 PPM and look at how the number of tablets will vary.

If you get a tablet number with decimal points, you can round that number up or down and set the calculator to “Amount of PPM” (Under the “What do you want to calculate?” drop down box) to figure out what you’d be getting in the PPM range using whole tablets… which may be a lot simpler than cutting the tablets into halves or quarters!

One treatment will purify the water, but you can toss the same number in weekly if you want to retain the ClO2 benefits. You may also want to treat more frequently if there is a significant influx of new water, such as after a heavy rain. If the water level rises visibly, you may also want to add an extra tablet or two.And best to treat at night as UV light degrades chlorine dioxide.

Warm regards,

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