Target vs. Minimum FC? Cost Implications?


Jun 21, 2019
Louisville KY
Hi. I'm a new above ground vinyl 16,000 gal pool owner in southern Indiana (came with the house.) I have LOVED this website and learned SO much the past month. I am actually enjoying learning about the pool and how to maintain it. I'm pretty much following all the advice here for testing, balancing, etc. and have actually abandoned the previous owner's in-line AquaSmarte puck system in favor of almost daily liquid chlorine addition.

Now, I finally have CYA at 30 (up from 0 at open), and everything else balanced. I've kept the FC pretty low so far at like 2 on average, to save money on chlorine. My question is, which is better - to keep FC at the recommended target level of 4-6, or, at the minimum level say 2 in order to save money on chlorine? Do you actually save MORE money by keeping FC at say 5, because it's in more of an equilibrium with the CYA, and it can be released over time as chlorine is used up? With FC being at 2, or 1.5, I feel like I'm just on the edge of "OK", and I'm waiting for 'bad things' to happen. (I haven't had many problems this month since opening.)

Is there a scientific, or cost-saving, or other reason to keep FC at Target level instead of at minimum? (I did a search and couldn't find this info - forgive me if I missed it.)



Bronze Supporter
Aug 15, 2017
Hi Kristen,
Yikes! it looks like you like to live on the edge! The minimum is just that, a minimum below which you should never go. By skirting so close to the edge, there is no capacity to absorb any unforeseen circumstances that would drop you below the minimum (i.e. debris from trees, bird poop, inability to tend to the pool for whatever reason (it happens)). And, believe me, unforeseen happens. What is the saying, "life is what happens when you're busy making plans."

You won't save money by keeping your chlorine low (algae will take care of that). Raising your FC to the 4-6 range from 2, takes only a one time addition of additional chlorine (maybe a gallon or two) to raise you to the new target. Once there, you will be using the same amount of chlorine to maintain it as if you were maintaining at the lower level. That small investment is well worth it considering the alternative.

I stick to the upper end of my target range and never dip below the lower end and my pool sparkles like no other!