FC loss seems high

[Bama Rambler]

Have you checked everywhere possible for the water to travel? I'm thinking waterfall but any path the water can take? Have you ran water at shock level through every possible path?

It looks like something is growing somewhere that the water doesn't normally flow, and then when water does flow through there, you get a tremendous loss of FC.

By the way, the salt had nothing to do with it.

 

[Concho]

I've done nothing differently the past 4 or 5 days....just seemed really strange that several hours after adding the salt my FC dropped from roughly 12 to 3 . My kids did swim while I was adding the salt...if they all relieved themselves in the pool could that drop it that much? My dog jumped in for about 30 seconds as well.

 

[Bama Rambler]

Oh yeah, Dog's and kids are a sure recipe for falling FC.

 

[frogabog]

Algae Salt! HA!

(those who know me from last year will know what I mean)

OP - PUT MORE BLEACH IN NOW! Extra. This happened to me and it is inexplicable but I had to shock the pool after adding salt late one night because it took a dump to 0 in less than 8 hours iirc. I even posted here about it. Your best bet is to get on top of it and don't try to explain it. Yet... We'll discuss algae salt later because that's just how this frog rolls...

 

[Concho]

Should I take my FC up to shock levels and keep it there for awhile?

 

[frogabog]

I would. It dropped to 0. In my experience, sudden 0ppm events like this mean algae has the upper hand. When this happened to me I saw a slight green tint and a hint of aquarium stink within just a few hours. I began shocking and was actually able to consider it done in less than 12 hours (no overnight loss, no CC, no fish stink or tint, crystal clear). I believe that was due to the pool being in very good shape prior to this event. I caught it early as well. One of the benefits of BBB is knowing when something is wonky because you can see it in the test results. It allows you the opportunity to handle it effectively and much quicker than otherwise.

 

[Concho]

I guess this was just payback for the lady at the pool store telling me not to add salt!

 

[Concho]

So am I safe to assume that my problems are from only that certain batch of salt?.....I'm kinda scared to add more....even if I buy a different brand of salt. And is this something that is likely to effect the next person who buys the salt....or is it something specific to my pool conditions? My wife is gonna kill me again!

 

[frogabog]

This particular wonkiness is rare because salt should not affect chlorine in any way. Add electricity to salt water, and you get chlorine. It doesn't make sense in any way, but it doesn't mean it didn't happen. I wouldn't add more salt till you know you're back in check, just in case it happens again but don't be scared to add more if you want. It may or may not be the salt, and you may never know what caused it if it isn't the salt. Algae salt is more of a joke than a real thing...

It's also not the end of the world. Raise to shock level, test... see what happens. Swim if you like. Swimming at or below shock level is generally considered ok. Chlorine can be a wonderful thing, especially if you've got some of those teenage boys with athlete's foot :~} Consider this, one of the recommended treatment protocols for MRSA (staph) is to soak in a bathtub with a cup of bleach. Calculate a cup of bleach in say, 100 gallons. It's WAY over shock level.

 

[Concho]

Thanks for the help....one more question for anyone....my pool builder also has some sort of pool frog mineral thingymajingy, which said it has silver chloride in it.....is this something I can just turn off....or if I already purchased it should I leave it running? What does this do exactly to the water?

 

[Bama Rambler]

Search pool frog and you'll find more than you want to know. Suffice it to say turn it off and leave it off. Better yet, uninstall it.

 

[Concho]

So the pool frog system is used to inhibit algae? It seems the ones I've read about on this site use copper, zinc and silver....any reason mine would just contain silver? What exactly are the drawbacks to using this...staining? Just to reiterate....my pool builder had the pool frog inline with my trichlor chlorinator......so the idea is that the silver keeps the algae in check, and then he has me keep my FC between 1-2ppm to control everything else? I had ChemGeek explain to me the problems with low FC/CYA ratios....but I believe he said that 1-2ppm FC is still effective at killing bacteria and viruses, but that it is not good at preventing algae. So is the pool store theory that the silver prevents the algae and the 1-2ppm FC is still enough to kill everything else....even if my CYA is 150-200? Sorry if I'm not making sense but I've read about a thousand threads in the last two weeks and my head is about to explode....before I had my issues several weeks ago I had about zero knowledge on my pool. Right now I have all my inline stuff turned off and have been just using bleach and some MA until I get my head straightened out.

 

[chem geek]

According to the Pool Frog FAQ, it says their system contains silver and limestone (calcium carbonate). Their EPA registration shows the product contains silver chloride. So it does not appear to contain copper.

Though copper is a very effective algicide (though has side effects of potential staining), silver isn't nearly as good especially at the low levels allowed for use in pools (typically < 40 ppb to prevent staining). Silver is better at killing bacteria, albeit slowly. So the lower FC/CYA level that I mentioned in an earlier post that could be OK if one were using an algicide probably doesn't apply to you with the Pool Frog. It might be OK or it might not, but personally I wouldn't risk that and would instead maintain a minimum FC that is around 7.5% of your CYA level so with your CYA of 150-200 ppm that would be around 11 to 15 ppm FC. In practice, I suspect that so long as you kept it no lower than 10 ppm you'll be fine until such time as you do a partial drain/refill to dilute the water. The biggest problem with the high CYA level is that it takes a heck of a lot of chlorine to shock the pool to get rid of algae if you are lax and it starts to grow (i.e. shock level is very, very high -- so in practice you'd end up having to use other methods to kill the algae unless one diluted the water to lower the CYA first).

 

[Concho]

So i'm better off just keeping my FC at 7.5% of my CYA level...which is around 80 (I'm working on lowering it). And the pool frog really isn't helping me out much? Is it doing any damage leaving it on? And you would still say my pool builder is having me roll the dice by telling me to keep my FC at 1-2ppm with no regard to CYA? I guess what I'm asking is say, for example, my CYA was at 40...all my other numbers were in line...would I run into problems if I ran the pool frog and my chlorinator and kept my FC at 1-2ppm, like my pool builder says. It seems like you're saying is that would be OK until the CYA got out of hand and I happened to get algae....would you agree with that? I was also going to add some borates which would help with the algae prevention too, right? I'm not saying this is how I want to operate my pool...just trying to somewhat get in my pool builders head to see what he's thinking (other than selling me stuff).

 

[JasonLion]

The pool frog runs some chance of causing metal stains regardless of FC level. It doesn't do enough to be worth risking those stains. Getting stains is unlikely but removing them is such a pain that even very low odds make it a bad tradeoff.

Trichlor works wonderfully, until CYA gets too high. Then things become very problematic until you replace water to lower the CYA level. The initial "works wonderfully" period is long enough to prevent you from blaming any problems on the builder.