Switching from Sustain Cal-Hypo to BBB

[amber]

Thank you!

I have a couple questions about starting BBB. How often do I do the overnight FC loss test?

Also, how exactly should I start the switch? I assume I have to figure out how much chlorine my pool will need a night? My target FC is 3-6 so if I am going to be adding the bleach at night do I add enough to get me to 6 or do I need to add enough to get me higher than that to keep it in range until the next night?

[chem geek]

You only do the overnight FC loss test when you suspect a problem, such as losing chlorine faster than normal for your pool.

To switch, you just start using chlorinating liquid or bleach as your primary source of chlorine. However, with the Sustain Shield chemical in the pool, it's unclear how to deal with that and transition to using CYA. The only clear-cut way is a full water replacement, but perhaps you can transition over time. If you see the chlorine loss increasing during the day but not at night, due to the Sustain Shield slowly getting diluted out of the pool, then you can increase your Cyanuric Acid (CYA) level. Unfortunately such an intermediate combination isn't something we know anything about nor have documented for what to do.

As for how much chlorine to add, you add whatever is needed to not go below the minimum in The PoolSolutions Best Guess Swimming Pool Chlorine Chart, but that would be after you get rid of the Sustain Shield from your pool. As purely a guess, I would follow this chart when the CYA level gets higher, but when it's below 30 ppm CYA as it is right now I'd still have a minimum of 3 ppm FC at all times. As Ben mentioned, you can use Polyquat 60 weekly as insurance to prevent algae during this transition period until the Summer Shield goes away.

[amber]

Thank you!

[CarlD]

Jumping here in the middle.
I'm wondering if the "Sustain Shield" is nothing more than slow-dissolving Cal-Hypo. After all, the "special" stuff was 62 or 68% cal-hypo...which is the NORMAL percentage of Cal-Hypo.

If so, then it has obviously NO effect on CYA.

The B-B-B system is really replacing the $$$ and guessing with knowledge of what stuff does and when to use it.
B: Bleach, B: Borax, B: Baking Soda, plus, of course, CYA and Muriatic Acid are basically all you usually need.
BUT

At the beginning of the season, when my CYA levels are low and my pH may be higher than I like, I like to use Tri-Chlor tabs to start because they add acid and CYA while maintaining chlorine. If the CYA is low but the pH isn't high, I may well use Di-chlor powder...because it doesn't lower pH much but adds even more CYA than Tri-Chlor, and I think faster than CYA powder.

I rarely use Cal-Hypo. It's getting harder and harder to find 68%--it's all that 48% garbage. I don't need calcium in my vinyl pool, so...unless I cannot get bleach or LC (my preference) I don't buy it. But I did in the past and used up what I had.
The two most important measures in your pool care are chlorine and pH levels.

CYA is third because it determines what the optimum chlorine level is. T/A is useful if your pH is unstable because adjusting T/A can stabilize it. And, unless you have a concrete-tile-type pool, Calcium is only important if it's too high, high enough to cause problems.

Finally, sometimes people have metal problems but those have very distinctive symptoms and even then, the solution is straight-forward.

What's my point? B-B-B is a KNOWLEDGE system that makes pool care super-easy and obvious and removes the mystery--and expense.

Pool Forum was the first to advocate for B-B-B and it has been picked up by TFP and other swimming pool sites. B-B-B (or "BBB" as most put it ) is a nice convenient shorthand for the key elements of what makes it all work.

No mystery!

[PoolDoc]

There are appear to be 3 parts to the system: slow dissolving cal hypo; fast dissolving cal hypo; and the imidazolidinone + salt "Shield". There may be additives with the cal hypo tablets that are part of the system, that don't have to be listed, but it can't be cyanuric acid. Likewise the imidazolidinone doesn't have to be listed, even if is the central pillar of the "Sustain" system.

Cal hypo is a great pool chlorinator . . . IF you use it the way I've occasionally described. The Sustain tablets make it possible to use cal hypo via the skimmer, which maximizes the positive characteristics of chlorination by cal hypo.

Actually, as a result of this discussion, I'm considering suggesting that people with metal problems see if they can buy the Sustain blue (slow) tablets to chlorinate with, since their use will have a very positive effect on metal clean-up. The main problem I currently see with this is the extreme high cost for the tabs -- $8 / pound at a1poolfun.com, which is the only online source I've found so far.