Just a few tiny spots - CC still under 0.5 - time to SLAM?

[blueheeler]

My free chlorine was a little too low (running between 3-5) instead of 7 for this past week. Yesterday I noticed a couple small algae deposits which can't be brushed off. My combined chlorine has climbed from 0.2 to 0.4 today.

I brought my free chlorine back into the recommended range and combined chlorine is still below the SLAM threshold (it's been between 0 - 0.2 until now).

Does the visible presence of any algae mean you must SLAM immediately? Or can I maintain a FC of 7 and let the chlorine gradually do its work?

I also realized yesterday that I've been breaking another rule too. I've been adding acid and bleach too closely together. This is a big no no, I guess? If I have to adjust pH, I usually add a small amount of acid in front of each return (with the pump running). Then I wait for approximately 5 minutes before repeating the same process with the bleach. Why is this such a bad thing? I don't smell any gas forming when I do it this way and I figured that the acid had enough time to dilute before adding the bleach. Am I wrong?

 

[woodyp]

What color is the algae that you "can't brush off"? Easier, quicker, and cheaper to SLAM it sooner rather than later. You might try a "puck" on top of those spots to see if it helps any first. Just rub it around. Welcome to the forum.

 

[tim5055]

My FC chlorine was a little too low (running between 3-5) instead of 7 for this past week. Yesterday I noticed a couple small algae deposits which can't be brushed off. My combined chlorine has climbed from 0.2 to 0.4 today.

I brought my free chlorine back into the recommended range and combined chlorine is still below the SLAM threshold (it's been between 0 - 0.2 until now).

Does the visible presence of any algae mean you must SLAM immediately? Or can I maintain a FC of 7 and let the chlorine gradually do its work?

I also realized yesterday that I've been breaking another rule too. I've been adding acid and bleach too closely together. This is a big no no, I guess? If I have to adjust pH, I usually add a small amount of acid in front of each return (with the pump running). Then I wait for approximately 5 minutes before repeating the same process with the bleach. Why is this such a bad thing? I don't smell any gas forming when I do it this way and I figured that the acid had enough time to dilute before adding the bleach. Am I wrong?

Algae = SLAM

While you may have had no problems with adding chemicals too closely together in the past you never know what the future brings. It is just good practice to spread the additions out more.

 

[blueheeler]

The algae is kind of brownish and forms on rough spots and cracked areas of the pool (in total about 4 trouble spots in my pool). I guess it's time to SLAM.

Thanks, lesson learned!

 

[jblizzle]

Welcome to TFP!!!

You certainly never want to mix the acid and bleach together, but once they hit the water and are mixed, there is very little if any danger of a problem even with only 5 minutes between them.

 

[duraleigh]

If it's brown and will not brush off, I am not so sure that's algae. Hold on the slam a bit and post a pic if you can.

Is it rough to the touch?

 

[blueheeler]

If it's brown and will not brush off, I am not so sure that's algae. Hold on the slam a bit and post a pic if you can.

Is it rough to the touch?

Too late! I added two 121 oz jugs of 8.25% Clorox. My FC is now at 23.5 and CC is 0.5. I'm pretty sure I have a little algae, just not a full blown bloom (yet). I also noticed a slight haze of green algae clinging to my Hayward pool vac yesterday.

The spots don't seem rough to touch. However, the spots tend to form wherever the plaster is rough like over cracks or protuberances. Unfortunately, these photos aren’t much to look at - the tea colored discoloration is more apparent to the naked eye.

https://drive.google.com/file/d/0BwhEYZLwq7FxVVNCd0o0YlhoUWc/view?usp=sharing
https://drive.google.com/file/d/0BwhEYZLwq7FxaF9FcmNzZTdFQ3c/view?usp=sharing

 

[blueheeler]

Great, thanks! I guess it makes sense to wait for the pH to stabilize before I add the chlorine anyway. But sometimes I am in a hurry!

 

[duraleigh]

That's not algae, I am almost certain. Looks like iron stains but that is very unusual to have them that size.

To test for iron stains, crush up several CHEAP Vitamin C tablets and put them in a sock and then hold them against the stain for 2-3 minutes. If it's iron, stain will lighten noticeably or go away.

 

[blueheeler]

That's not algae, I am almost certain. Looks like iron stains but that is very unusual to have them that size.

To test for iron stains, crush up several CHEAP Vitamin C tablets and put them in a sock and then hold them against the stain for 2-3 minutes. If it's iron, stain will lighten noticeably or go away.

I will give it a try. Supposedly my iron and copper are 0 (per the tests from the pool store), but who knows. If vitamin C works I will be a happy camper.

 

[duraleigh]

I have some iron stains in my pool and my iron test consistently says I have zero iron. I can't decide if that's because the iron has all precipitated onto the pool surface or the test is bogus at some very low level.

 

[blueheeler]

I have some iron stains in my pool and my iron test consistently says I have zero iron. I can't decide if that's because the iron has all precipitated onto the pool surface or the test is bogus at some very low level.

FYI I think my stains are calcium related. We have etching around the pool and a few calcium nodules (like little stalagmites). Each of the stains surround a calcium nodule. After researching TFP site some more I feel better. Originally, I thought the nodules were formed by letting the water get too far out of balance, but it sounds like instead my plaster is delaminating (probably a shoddy job to begin with). I can sand away the nodules and most of the staining with a pool blok pumice stone. Not good news, but at least it wasn't my fault!