NOOB questions on CYA testing and adjusting

[yawdro65]

First full season as a pool owner and things are starting to come together for me. I have a few newbie questions though.

I don't think my first CYA test gave me a result. The dot never disappeared and the graduations only go to a min level of 30.
1. Can someone describe what happens to the black dot in the bottom of the tube when doing the CYA test? Does it disappear, or does it look big and take over the whole bottom?

I've been open about a week and a half now and have been trying to SLAM my pool. I was losing chlorine through the day (FC=11 in the morning and FC=0.5 after work) but it was holding a lot better overnight (FC=11 to FC=7-8). I'm assuming I need to add CYA.
2. How do I add the granules? I literally poured the CYA granules into an old sock and hung it in front of my return jet. Is this the right method?
3. How soon can I test my CYA after my sock gets emptied out?

4. This isn't really CYA related, just a noob question. Is there any preferred way to orient the return jet eyes? I have 2 returns on opposite corners of the pool. I typically try to aim them somewhat sideways to try to get the water to circulate around the pool. I've seen other suggestions to point them to the bottom to turn the water over more. Just wondered if anyone had a preference/reason.

Thanks!

 

[Texas Splash]

Does it disappear

That's it! It should completely disappear. To increase CYA via granular stabilizer, place the required amount as calculated by the Poolmath calculator into a white sock and place in the poolside skimmer basket. For those concerned about suction flow to the pump, suspending the sock near a return jet or from a floating device will also suffice. Best never to allow undissolved granules to rest directly against the pool surface. Squeeze the sock periodically to help it dissipate. Once dissolved, consider your CYA adjusted to that programmed (target) level. CYA test readings should show a rise in 24-48 hours, however some pools may experience a longer delay to fully register. Best to confirm final CYA in about 5-7 days before adding any more stabilizer/conditioner.

This isn't really CYA related, just a noob question. Is there any preferred way to orient the return jet eyes?

Not really. Every pool is different. Enhancing water surface movement is quite common, but some folks like jets to push water lower for better circulation at different depths. Really whatever works best for you.

 

[drharris]

With only two returns, I'd keep them pointed for surface movement. You probably have a main drain, and that's likely enough to keep the deep end decently circulated. If you want to calibrate the jets better, put ping-pong balls in each corner of the pool, and make sure they arrive in your skimmer. Usually that's enough to see if you have any dead areas.

 

[AftonJeeper]

Here is a link from the pool school extended cya test page. Shows the dot in the 3 stages of the test.

 

[yawdro65]

Awesome! Thanks for the replies!
I don't have a main drain in the deep end so I guess I'll keep messing around with the jets to see what helps keep it cleanest. I personally like circulating the top to help skim so far.

AftonJeeper - thanks for the link! That's exactly what I was looking for. Not sure how I didn't see that before when looking through pool school. I've been really disappointed in the CYA test with the K-2006. All the other tests have nice color changes that make it very clear what's happening. The disappearing dot seems so unscientific.

 

[Dmanderson21]

I'd like to piggyback on this thread as a newbie myself having finally had my cya levels bottom out after the pool builder increased my level to over 70 at startup...

I've now gotten a little on the low side (~35) as the sun is burning off my chlorine quicker than previously (pool gets full sun most of the day). I understand how to go about adjusting but given it takes about 24 hours to dissolve do I wait until after all the granules have dissolved before adjusting my chlorine to the corresponding cya level? Or is it best to immediately adjust even if things are still dissolving

 

[drharris]

The disappearing dot seems so unscientific.

It's a turbidity test. Thinking about it, CYA is a weak acid, so how do you measure it independently of pH value? There's probably a way with the traditional titration type of tests, but would it be easy for the layperson to perform? Likely not very easy. So turbidity, or "haziness" of the water happens to be the easiest way to go about it for the average person without spending a ton on reagents for some other kind. It seems weird, but it's just as scientific as titration tests, just a little more subjective until you get really familiar with it.

Or is it best to immediately adjust even if things are still dissolving

Go ahead and immediately adjust, if it's still within the SLAM level of current CYA. It will be a little harder to maintain until CYA remains firm, but keeps you from getting into a bad situation. It's safe to swim up to SLAM level, so it won't hurt.