Our pool has been black for a month

[Dirk]

The unicorn of pool sanitization is a time-release "pill" of chlorine. We'd all love to have one, but there's no such thing, because chlorine needs something else to bind to in order to be in solid form. That something else, in terms of residential pool care, is either CYA or calcium (but not both). So if you want to sanitize a pool with chlorine in solid form, you typically use DiChlor, TriChlor, or Cal Hypo. DiChlor and TriChlor are chlorine and CYA. Cal Hypo is chlorine and calcium. So when you write "Cal Hypo / CYA puck," there would be no such thing. Cal Hypo doesn't have any CYA (stabilizer) in it.

If you use TriChlor pucks, your pool will eventually accumulate too much CYA (stabilizer), because the CYA doesn't evaporate so it accumulates.
If you use Cal Hypo, your pool will eventually accumulate too much calcium, because the calcium doesn't evaporate so it accumulates.

Too much of either CYA or calcium will eventually cause problems, necessitating a water exchange to reduce either. Too much calcium is not as bad in a vinyl pool as it would be in a plaster/pebble pool, but it will eventually cloud the water. Which is why, for the most part, we encourage folks to use either liquid chlorine, or a saltwater chlorine generator (SWG), as they only put chlorine in the pool and nothing else.

Personally, I wouldn't own a pool without an SWG, and most that have one feel the same way. I already have too much calcium in my water, so would never use Cal Hypo. And I tore out my tab feeder when I installed my SWG, so no pucks for me, either.

@Newdude, can you "check my math" on this post? I've never used anything but liquid- or swg-chlorine, so had to look up most of what I just shared.

 

[Newdude]

can you "check my math" on this post? I've never used anything but liquid- or swg-chlorine, so had to look up most of what I just shared.

You looked it up well.

 

[SpongyMothKilledOurPool]

OK I did the little daily duo Chlorine/pH test, confirmed basically no chlorine, and unchanged from pool store's test of >8.2 pH:



The store that supposedly had CYA in stock at that location... did not. So we still don't have any of that, so I've started with 3.5 cups of MA per PoolMath's advice. It's been almost an hour, so maybe I'll head out there & add liquid chlorine in a few minutes. Should I go ahead & re-test pH for fun or is it too soon?

Here's what our pool water looks like currently:


Here's what it looks like when you stir up caterpillar poop from the bottom:



But this only happens in certain spots now, not everywhere.

Bout to go out & change the filter for the 3rd time today, as it has almost instantly re-clogged after I brushed the bottom a few minutes ago to avoid settled acid (I didn't brush immediately because all the threads I looked up about how to handle MA just talked about how to pour it in, & almost none of them mentioned brushing).

 

[IceShadow]

If you pour it in at a return it should distribute quickly without needing to brush.

30 minutes of circulation is usually enough to test again. 60 is a safer bet.

 

[IceShadow]

I would do an ammonia test to be safe. Add enough LC to get to 10ppm. Let circulate 15 mins. Let us know if it holds any chlorine after 15 minutes.

 

[Dirk]

If you pour it in at a return it should distribute quickly without needing to brush.

That's how I do it. The size of the stream as you pour should be about the size of a pencil, so pour slowly.

 

[Dirk]

Here's what it looks like when you stir up caterpillar poop from the bottom:

What happened to the vacuuming? The more of that gunk you can remove, the faster you'll get this cleaned up. If you're counting on only chlorine removing that stuff, geez, that will be a very long haul.

 

[HermanTX]

Bout to go out & change the filter for the 3rd time today, as it has almost instantly re-clogged after I brushed the bottom a few minutes

Are you able to vacuum to waste rather than just putting everything through the filter? It would be best to let it all settle then vacuum to waste (cannot remember if your plumbing can do this). You then will need to add water and obviously this affects your pool chemical balance but doing what you are doing - it may be worth it.

 

[YippeeSkippy]

l think raking it out would be preferable.

 

[wireform]

And arm yourself with lots of GALLONS of chlorine.

 

[SoDel]

I would prioritize what @IceShadow is saying (post #125). Get and maintain chlorine in that pool. The organic matter is just multiplying like widlfire. You can continue to test pH up to 10 ppm chlorine, and beyond that with your pH meter. The CYA will protect the FC from the sun but your OM is going to eat FC faster than the sun for a while. I’m trying to say, yes get your CYA and pH right but all that is intended to serve the utility of the main attraction — chlorine. Don’t be shy with chlorine when managing your CYA and pH. It probably seems like a lot to do all at once, and it sorta is.

 

[SpongyMothKilledOurPool]

Something interesting happened... We're now around 2 hours after having added the MA, and there are little brown clumpies floating at the top of the water now (the brown sludge from the bottom coagulating?).

What happened to the vacuuming? The more of that gunk you can remove, the faster you'll get this cleaned up. If you're counting on only chlorine removing that stuff, geez, that will be a very long haul.

I'm still vacuuming, but I've only been doing 3 or 4 vacuum-loads at once, once or twice per day, because it's a real hassle to pull it out, open & rinse everything after only a minute or so of vacuuming.
HOWEVER: A big part of why it's been super annoying to rinse the vacuum filter, is that in the past few days the garden hose's sprayer attachment has been popping slightly off the end of the hose increasingly often--just enough to blast water in reverse straight at your crotch instead of where you're aiming it--to the point that I have to try and screw it back on "straight" & "tight enough but not too tight" a half dozen times prior to each instance of turning it off & on to hose down the vacuum filter or the pool's cartridge filters.

It looks like the fault lay with the fittings on the end of the hose, and I have just now found & set up a different hose which (so far, pray for me) seems to hold the spray nozzle on securely. So I can probably start to do more frequent sets of vacuuming, & more back-to-back rinse/repeat cycles, without losing my mind about the *!@% (^&$ing hose attacking me.

I just retested chlorine & pH (with the quick daily dual test) and they still look the same. I'll go dump in my first bit of liquid bleach in a minute.

I would do an ammonia test to be safe. Add enough LC to get to 10ppm. Let circulate 15 mins. Let us know if it holds any chlorine after 15 minutes.

The big fancy test kit I got didn't include ammonia! Do I need this??

When you say "add enough LC to get to 10ppm" do you mean effectively start the SLAM? Because my pH is definitely not yet in range (nor my CYA). Or is this just one exploratory shock to see if the chlorine disappears immediately?
When you say "add enough LC to get to 10ppm" do you mean, "do what Pool Math says is the dosage to get to 10ppm, then test after 15 minutes to see how much it's gone down?"
Or do you mean "add LC until a chlorine test says you're AT 10ppm, then test 15 minutes later to see how much it's gone down"?
And we're talking FC as the test/measure, right?
Is that advice moot if I have no way to measure Ammonia?

 

[Newdude]

And we're talking FC as the test/measure, right?

Correct. Ammonia will eat 80%+ of your FC in 10 mins. If you add 10ppm per poolmath and have most of it left after 10 mins, there is no ammonia.

 

[SpongyMothKilledOurPool]

l think raking it out would be preferable.

Does raking mean, using the net on the long pole? The stuff mostly dissipates back into the water & doesn't get caught very well with the nets (even in the new, clumpy floaty form photographed above).

 

[wireform]

That will test for ammonia if it's present. If it holds onto 5ppm for 10 minutes your golden but if drops to 0 then keep pouring it in until it holds then it basically nixed the ammonia but you need to keep the slam moving forward at this point.

 

[SpongyMothKilledOurPool]

Correct. Ammonia will eat 80%+ of your FC in 10 mins. If you add 10ppm per poolmath and have most of it left after 10 mins, there is no ammonia.

What's.... what's the cure if I have tons of ammonia?

After googling tannins & ammonia, I bet we've got plenty (oak trees)--as apparently tannins can trap ammonia and/or inhibit bacteria that break ammonia down?

 

[SpongyMothKilledOurPool]

OK adding some liquid chlorine stat. Taking a step back to MA for a second, how long should I wait between large doses of that? Especially considering old vinyl pool, & less than great circulation due to the filter clogging so quickly. I did pour it in front of the return, but I'm not sure how great my aim was so I'm not confident that none of it will settle when I do this.

 

[wireform]

Brush well 4 ft either side of the pour spot and as far out as the pole reaches across the floor since chlorine is heavier then water it'll sink to the floor and can bleach the liner.

 

[IceShadow]

OK adding some liquid chlorine stat. Taking a step back to MA for a second, how long should I wait between large doses of that? Especially considering old vinyl pool, & less than great circulation due to the filter clogging so quickly. I did pour it in front of the return, but I'm not sure how great my aim was so I'm not confident that none of it will settle when I do this.

Add to 10ppm. Test after 15 minutes and see if you have FC. If not, it’s likely you have ammonia.

If that’s the case we can talk next steps. It’s either dump a lot of chlorine in (10ppm at a time and keep going with testing every 15 mins and adding and testing, etc, until it holds FC) or exchange water. It’s a gamble. You could, if the FC disappears that fast, get an ammonia test from a fish store to approximate how much FC you’d need, but first let’s see if the pool consumes FC that fast or not.

 

[SpongyMothKilledOurPool]

Add to 10ppm.

Does that mean "add the quantity Pool Math says will get me to 10ppm"? Or does that mean "keep adding chlorine & testing till I see 10ppm"? Prior to doing the "how many ppm are left 15 minutes later" bit.

I just added a full 128oz bottle which is what Pool Math said should get to 10ppm, and my first test (after brushing, so maybe up to 10 minutes after pouring) is reading 2ppm.