High FC consumption post-purge

[Nackle]

I purged my hot tub yesterday with Ahhsome. After the purge, I had an overnight FC loss of 3. My hot tub requires a really low CH which means I need to use an expensive Vanishing Act product to pull the CH down. I don’t want to use it if I haven’t actually taken care of whatever problem was pulling down my FC.

Here’s the full story:

For 3-4 weeks, my hot tub has had moderate FC consumption. I saw overnight loss between 2 and 4 most often. Since it has been ridiculously cold, I’ve been trying to SLAM it, but that didn’t fix the problem. I still saw typical FC loss of at least 2 and CCs were almost always 1.5 even after two weeks of SLAMing.

It has finally warmed a bit, so yesterday I added Ahhsome, ran the jets for 30 minutes, and got some gunk. Without draining, I added another half dose of Ahhsome and ran the jets for another 30 minutes. The foam was nearly all white. I drained, wiped, and rinsed. I refilled and balanced the water. I dosed to 5 FC. Before bed, I tested and found that FC had already dropped to 2. I added enough dichlor to get back to 5 and went to bed. This morning, my FC was back to 2.

I’m wondering whether this consumption is normal after a purge. If it’s normal, I want to get the Vanishing Act pillow in so that I can keep my manufacturer happy. If it isn’t normal, I should probably purge again

Can I conclude anything yet? Was my purge insufficient and I need to do it again? Could I just be dealing with exposed bacteria that are soon going to be dead and I should just keep the FC at 5? Do I try a one day SLAM and push the FC up to 10?

 

[Bperry]

I purged my hot tub yesterday with Ahhsome. After the purge, I had an overnight FC loss of 3. My hot tub requires a really low CH which means I need to use an expensive Vanishing Act product to pull the CH down. I don’t want to use it if I haven’t actually taken care of whatever problem was pulling down my FC.

Here’s the full story:

For 3-4 weeks, my hot tub has had moderate FC consumption. I saw overnight loss between 2 and 4 most often. Since it has been ridiculously cold, I’ve been trying to SLAM it, but that didn’t fix the problem. I still saw typical FC loss of at least 2 and CCs were almost always 1.5 even after two weeks of SLAMing.

It has finally warmed a bit, so yesterday I added Ahhsome, ran the jets for 30 minutes, and got some gunk. Without draining, I added another half dose of Ahhsome and ran the jets for another 30 minutes. The foam was nearly all white. I drained, wiped, and rinsed. I refilled and balanced the water. I dosed to 5 FC. Before bed, I tested and found that FC had already dropped to 2. I added enough dichlor to get back to 5 and went to bed. This morning, my FC was back to 2.

I’m wondering whether this consumption is normal after a purge. If it’s normal, I want to get the Vanishing Act pillow in so that I can keep my manufacturer happy. If it isn’t normal, I should probably purge again

Can I conclude anything yet? Was my purge insufficient and I need to do it again? Could I just be dealing with exposed bacteria that are soon going to be dead and I should just keep the FC at 5? Do I try a one day SLAM and push the FC up to 10?

Looks like “vanishing act” ingredients are a trade secret and so would not be something TFP recommends. There’s no way the product can remove calcium from the water, it may just hide it from testing or convert it to some other compound.

For the FC test you need to test it much sooner after adding chlorine to know how much you lost overnight. Try waiting 5 minutes with the jets running. It doesn’t work to add enough to theoretically get it to 5ppm. The OCLT is designed to work such that you have to test the actual FC value. So I don’t think you can say anything really, except I doubt you need the fancy calcium remover that doesn’t actually remove calcium. But maybe some more knowledgeable folks can chime in on that.

 

[Gebo]

I am in no way an expert in hot water chemistry. I know nothing about a SWG system. But I have a couple of questions. Which Ahhsome did you use? The gel or the AquaClarity? How much did you use? I see your tub is 455 gal. I ran probably 6 + cycles of Ahhsome gel and let it sit overnight and ran it again. Overkill? Probably. I ran it over and over until there was virtually no gunky residue around the sides of my tub.

What are you slamming with? When I slam with liquid chlorine at a CYA of 30 I need to get my Cl to 12 ppm minimum. Maybe you just need to crank up the chlorine????

This will get some interesting comments but once I added an enzyme product and added AquaFinesse 2 weeks later, my chlorine consumption dropped dramatically. It seemed CL really leveled out. I was getting so upset every morning when my sight glass was clear that I had started to contemplate a FROG@EASE set up. 4 ppm of Cl would disappear from 11 pm to 7 am. My wife sears she didn't pee in it. Now, can I prove and enzyme or AquaFinesse fixed my problem? Absolutely not. Do I think it (they) had something to do with leveling out my chlorine levels? Yes. I'll be able to come to better conclusions in 2-3 months.

Everybody's hot tub is not the same. Vanishing Act is recommended by Hot Springs. Reputable company. Somehow it soaks up the calcium. Seems logical.
I don't much about it but I would still try and eliminate the Calcium before it got in my tub.

And for your back up plan, purge again with Ahhsome until you don't see any gunk and then drain and refill and start over.

Reminder, I have only had a hot tub 4 months. Take what I say with spoons of salt....LOL

 

[Nackle]

Thanks to both of you for your replies.

If you’re interested in learning more about Vanishing Act, you can search through the TFP forums. The best guess is that it works like a water softener—it likely has a similar material inside the bag as the beads in a water softening machine that “grabs onto” the calcium. It definitely does remove calcium.

I purged with the regular Ahhsome gel (not the Aqua Clarity) and used about 4 teaspoons for the first round then two teaspoons for the second. I’ve been thinking about buying the Aqua Clarity for weekly dosing. Maybe I should!

When I was SLAMming before the purge, I was cranking my FC to 10 with liquid chlorine. (My CYA was just shy of 20.)

 

[Bperry]

Thanks to both of you for your replies.

If you’re interested in learning more about Vanishing Act, you can search through the TFP forums. The best guess is that it works like a water softener—it likely has a similar material inside the bag as the beads in a water softening machine that “grabs onto” the calcium. It definitely does remove calcium.

I purged with the regular Ahhsome gel (not the Aqua Clarity) and used about 4 teaspoons for the first round then two teaspoons for the second. I’ve been thinking about buying the Aqua Clarity for weekly dosing. Maybe I should!

When I was SLAMming before the purge, I was cranking my FC to 10 with liquid chlorine. (My CYA was just shy of 20.)

Oh, it’s some kind of filter? The picture just looked like a bag of powder. I will take back my statement about it not removing calcium and change it to I’m not convinced it’s needed.

But you need to do the OCLT the recommended way to be able to use it to know if consumption is reasonable or not. The test needs actual test results not predicted results.

 

[Mdragger88]

You’ll probably never pass an oclt with zero loss in a hot tub but doing an oclt is still a good metric for seeing where you stand. If it were me I’d raise to slam level - which is 10ppm even if you have no cya. Got any cc’s now?
If so slam until there down to .5 or less.
I imagine you just unearthed some stuff that the fc is working on.