Overnight Chlorine Loss Test

[drrayb]

I have a question. Is there any point to doing OCLT if you have tons of leaves/seeds falling into the pool...thats a known consumer of chlorine. I get tons of dead algae every day but I imagine if I slam, it wouldn't matter because new Crud is just going to fall in every day...

TIA

 

[ajw22]

What is your daily FC consumption?

 

[drrayb]

I would estimate 3ppm.
Full disclaimer i dont have a solid test kit yet, so just going off pool store results. But I ask as more of a general question...

its a 20,000 gal IG pool, in full sunlight, with about 40 of cya. I keep the chlorine above 5 and I have almost a full skimmer every morning

 

[ajw22]

I don’t think your leaves/seeds are the big consumer of chlorine you think they are.

Having algae growing in the water is very different then leaves/seeds.

 

[drrayb]

Oh, I assumed the leaves were providing substrate/nutrition for the algae to grow and that even if I nuke it to 0, the first one that falls in will help start more algae

 

[ajw22]

If you maintain the proper FC/CYA ratio then it can keep a pool algae free with stuff falling into the water.

 

[Newdude]

Hey D !!!

My last house was heavily treed and pulling crud from the pool was all season long. What I found was that anything fresh was not detectable, even the brown leaves in the fall. It had to be decaying and full of bacteria (etc) already. So either a rotten branch would have to fall, or the leaves had to sit in the pool for the winter festering first.

 

[Jimrahbe]

dr,

Leaves and crude are just excuses that people use as to why they have algae. Rainstorms are another one.

Jim R.

 

[drrayb]

Lots of heavyweights weighing in. Thank you all! I guess the answer is to slam . I will get on it as soon as the test kit arrives.

Another question - can dead algae seed more live algae? Do i have to constantly vacuum it to waste or can it go through the sand filter?

 

[Newdude]

Do i have to constantly vacuum it to waste or can it go through the sand filter?

Filter it and then backwash at 25 % PSI increase over the clean reading. Deep clean the filter after the SLAM if needed.

I guess the answer is to slam

Rookies try to avoid SLAM. Pros SLAM because they had a tingle of a feeling and can quit 12 hours later because it was a false alarm when they pass the OCLT. You are free to guess who gets caught behind the ball here.

Fire when ready. We'll help.

 

[drrayb]

Hi all, the tf100 arrived and i tested this morning. Here are the results

Ph - no idea. Photo attached. 7.6?
FC 6.5
CC 0.5
Ca hardness 300
TA 190 (guess i threw in too much baking soda at opening...)
Cya ~ 25

Ill do the OCLT tonight, but after vacuming and swimmers last night there was again lots of dead algae on the floor this morning..

 

[ajw22]

Your CYA is 30. We round up. If the dot disappears between 30 and 20 we round up and call it 30.

Your pH is in the 7's which is good. Call it 7.6.

Overall you look good. Don't worry about your TA. Just keep your pH in the 7s.

 

[IceShadow]

Reduce pH to 7.2 and slam away

 

[drrayb]

Ok soo...i checked the FC last night. After a hot and sunny day it went from 6.5 to 2.5. The drop this morning was only 0.5 suprisingly

So it drops 0.5 overnight but still has dead algae. Maybe its old dead algae that the robot kicks up but doesnt remove?

Why do I still occasionally see a green spot on a wall or corner...

Thanks all for your expertise

 

[IceShadow]

2.5 is really low. Your CYA is about 30. Shouldn’t let it get down there. Keep it up around 8 when you add daily, and by the next day it shouldn’t be lower than 4. If it is and the OCLT is passing, your CYA is too low for your area and the sun your pool is getting.

Might be a little spot somewhere hiding a tiny outbreak. Scrub the pool down well and any hidden areas like light niches, ladders, etc.

 

[drrayb]

Just an update, it turns out the dead algae was just being kicked up, not being sucked up by the robot. A vacuum got rid of all of it and it didnt really reform. Good times. Thanks for your advice.

I also took the cya up to 50 and keep the chlorine high as per the table.