Slam questions

[Blivit79]

..well, more than just slam questions but anyway.

I have been maintaining my first pool with help from threads here for a little over 1 year now. In that time my water has always been clear. I record my tf-100 results and add what pool math tells me to add.

I had to go out of the country on business for 2 weeks. I left my wife with what I thought was enough info to maintain the pool while I was gone. I didn't have her do anything as I assumed basic fc and ph tests and adding the necessary amount of bleach or muriatic acid would be enough. I showed her how to turn on the vacuum and to run that 2 days per week as I had always done.

Anyway, by the 4th day or so she tells me the pool is turning green. Test results seemed fine though and we continued to add bleach as indicated. It kept getting worse according to her (the green) so I just knew I would be in for some fun when I returned.

Yep, its green. However, even in this state the test results were not as bad as I thought they would be:

FC: 2
PH: 8.2
CH:275
TA: 70
CYA: 40

I knew I would have to slam so I started working on getting the ph down to around 7.2 while still adding some bleach. I also had to drain some water as the level was a bit high from all of the rain here. Once that was done I worked out what I needed to add bleach wise for the cya that I had and needed to wait another day as I was out of bleach.

Today then started the slam. PH was around 7.2, pump set to run 24/7 and bleach stocked up. Started at 12pm today. Got the FC up to slam level (overshot it to 23 instead of 16...not on purpose) and have been testing every 3 hours to see what it is doing.

Questions:

1. I have a 2 speed pump. Is it ok to run on low speed only during slam?
2. I am not seeing FC drop at all so far. I thought it would. I have never slammed before; is this normal? It hasn't been 24 hours yet.
3. By overshooting the FC level, is that causing an issue? Since that initial add, I have not added any more bleach.

I still find it odd that the test levels were not horrible while the pool was green. I still am not sure what happened. Maybe the vacuum wasn't run...maybe it was from all of the extra rain while I was gone...who knows.

 

[duraleigh]

run the pump at normal speed. You need filtration to complete a SLAM.

Are you saying you still get a 23 ppm FC test result? That's OK but not what I would expect.

 

[Blivit79]

run the pump at normal speed. You need filtration to complete a SLAM.

Are you saying you still get a 23 ppm FC test result? That's OK but not what I would expect.

I have high and low speed on my pump. I usually only run high speed when I am running the vacuum. Will low speed be enough for the slam?

I was surprised to not see a loss in fc as well. It's staying there right now.

 

[pooldv]

Running on low is fine.

 

[Blivit79]

So I tested this morning at 5am. My fc went up to 25 from 23. How does that happen? It was dark so I couldn't see if there was any change in the color of the pool. The water definitely has a strong chlorine smell which it has never had so I know the level is high as it should be but again I thought I would be losing chlorine. Could there be a different issue with my water? Below shows the water right before I started the slam yesterday

 

[singingpond]

You don't have a SWG, by any chance? Just double checking.

Is the pool water murky or clear? It's a bit hard to tell from the photo because of the fence texture. It sure looks like a nice algae bloom... FC holding steady does seem very odd, with water looking like that.

What are you seeing for CC?

 

[Blivit79]

You don't have a SWG, by any chance? Just double checking.

Is the pool water murky or clear? It's a bit hard to tell from the photo because of the fence texture. It sure looks like a nice algae bloom... FC holding steady does seem very odd, with water looking like that.

What are you seeing for CC?

Water is clear; at least it is at the level I am puling my sample water from. I cannot see the bottom of the pool at all but I have swept the steps and there is a "dust" that comes off. This same dust though was present before I left when the water was good. I ran my vacuum yesterday (both manual and automatic) and cleaned the filter right before starting the slam.

CC has been around 0.5 at each test.

And no, no swg.

 

[Texas Splash]

Going back to the first post in this thread, your FC was definitely low. So if your wife wasn't able to keep that FC where it needed to be, that certainly explains the algae. Just to confirm, is there any chance your wife put anything else in the pool other than bleach and acid while you were away?

Can you confirm what percentage bleach you are using? Regular liquid correct?

An increase in FC makes no sense unless there was a counting error from the previous test. And by over-shooting your SLAM FC of 16 by an additional 7 ppm, you would expect that extra FC to get expended rather quickly by the sun. I'm curious now to know what your next FC and CC readings will be.

 

[Blivit79]

Going back to the first post in this thread, your FC was definitely low. So if your wife wasn't able to keep that FC where it needed to be, that certainly explains the algae. Just to confirm, is there any chance your wife put anything else in the pool other than bleach and acid while you were away?

Can you confirm what percentage bleach you are using? Regular liquid correct?

An increase in FC makes no sense unless there was a counting error from the previous test. And by over-shooting your SLAM FC of 16 by an additional 7 ppm, you would expect that extra FC to get expended rather quickly by the sun. I'm curious now to know what your next FC and CC readings will be.

I have no other chemicals besides the bleach and acid so no chance of anything else being added.

Bleach percentage I do not know 100%. It is bulk 2.5 gallon jugs that I buy from the pool store here. They told me it is 10% but who knows. I select 10% in pool math and always have.

We have had more rain. I know it rained last night.

Water will be tested again once I am home from work.

 

[pooldv]

Yes, that is likely 10% liquid chlorine. One additional comment on running the pump. Low is fine to save electricity. But, if you want to clear the pool faster running it on high will speed up the process. Especially when vacuuming or brushing. If you have a bottom drain and a valve to switch flow between skimmer and drain then I would run the pump on high and switch suction to the drain when brushing the pool. Also, keep an eye on the filter pressure, algae can clog a cartridge filter pretty quickly. Clean the filter when the pressure rises 20-25% over clean pressure.

 

[Blivit79]

Ok, something is wrong...

Tested today after work. It had rained again. So much so that I will need to drain water out of the pool. I had to wait until it stopped raining before I could test.

FC did not drop at all. Still at 25. CC still at 0.5 and no change in pool color. Pump has now been running for 30 hours on low speed.

I cleaned the filter and it had green stuff in it but not what I would call excessive. Put everything back together, turned to high speed and swept the sides/bottom. There is a significant amount of dust or algae or wherever this stuff is in the pool.

I don't know what to do here.

 

[pooldv]

It is dead algae. Maybe the pool gallons you are entering is off. Enter the numbers in Poolmath, add what it says with pump on high and test 15 minutes later to validate the dosage. It is also possible that the chlorine you are buying is 12.5%.

 

[Blivit79]

It is dead algae. Maybe the pool gallons you are entering is off. Enter the numbers in Poolmath, add what it says with pump on high and test 15 minutes later to validate the dosage. It is also possible that the chlorine you are buying is 12.5%.

My fc is already really high though and is maintaining. Is it ok to raise it? I have not added any bleach in 30 hours and the level is static.

I've been using 16k gallons and 10% in pool math for a little over 1 year and it always gets the dosage pretty close. I know it's not exactly 16k gallons but it seems to work.

I was under the impression that the point of the slam was to kill and oxidize the algae which would get rid of the green. Am I mistaken?

 

[singingpond]

Could you run a test with the OTO test that is included with the TF-100, just as a sanity check? It should be somewhere in the range of deep yellow to orange, I believe, with those FC levels.

It makes no sense for FC just to remain unchanged after a day of sun on the pool, even leaving aside possible organics in the water. How was the weather today, before the rain?

 

[Blivit79]

Could you run a test with the OTO test that is included with the TF-100, just as a sanity check? It should be somewhere in the range of deep yellow to orange, I believe, with those FC levels.

It makes no sense for FC just to remain unchanged after a day of sun on the pool, even leaving aside possible organics in the water. How was the weather today, before the rain?

OTO test is Orange.

Weather today was mid 90's and mostly sunny before the rain. Average central Florida weather for this time of year though the rain has been a bit excessive.

 

[Crackerjack4u]

Since you have to drain some water anyway, perhaps you can use that to your advantage, and do a vacuum to waste to drain it down to the level you need it to be, and also see what you are able to pull off the bottom?

 

[Crackerjack4u]

"My fc is already really high though and is maintaining. Is it ok to raise it? I have not added any bleach in 30 hours and the level is static." To answer your question on raising the FC, your suggested Shock level is 16ppm, if you are already at 25ppm, as long as you are certain nothing raised your CYA level while you were away, I wouldn't raise the FC any higher because you risk damage to your pool/equipment if you raise it too high.


"I've been using 16k gallons and 10% in pool math for a little over 1 year and it always gets the dosage pretty close. I know it's not exactly 16k gallons but it seems to work."

"I was under the impression that the point of the slam was to kill and oxidize the algae which would get rid of the green. Am I mistaken?" No you are not mistaken.

 

[Crackerjack4u]

Perhaps someone else will come along and be able to give you some ideas of why you are having no FC drops because it is odd. I'm curious to see if possible by morning we don't start seeing a increase in the CC level. Only time will tell, but for now I would let it ride and not add any more chlorine until the levels indicate the need to do so.

 

[Blivit79]

Perhaps someone else will come along and be able to give you some ideas of why you are having no FC drops because it is odd. I'm curious to see if possible by morning we don't start seeing a increase in the CC level. Only time will tell, but for now I would let it ride and not add any more chlorine until the levels indicate the need to do so.

Thanks. I have no problem riding it out if I knew there wasn't another issue. Maybe I am just paranoid. After reading a ton of other slam stories with people seeing a color change in under 48 hours and significant fc drop, I expected the same.

I'll see what happens tomorrow as I can't really drain any water out until then anyway.

 

[Crackerjack4u]

Yeah, I'm sorry that I can't tell you why it's not dropping yet, but just continue running the filter, backwashing, brushing often, and vacuuming to waste if possible instead of filter. Put a skimmer sock or knee high panty hose in the skimmer basket.

Hopefully it will soon do what it's suppose to do. I just don't want you to risk damaging your pool with any higher FC levels in there than needs to be.

Also if you don't mind can you fill out your signature information here's what they ask you put in it. http://www.troublefreepool.com/content/115-read-before-you-post

You can get to that page from here by going up to the top to the small tab called FORUM ACTIONS, then from the drop down there chose GENERAL SETTINGS, then look down the left side of your page for a Bold print category called MY SETTINGS and then click on EDIT SIGNATURE there. Fill in the info and you are good to go that way we know what size your pool is if its ABOVE GROUND, or In GROUND, what kind and size filter you're using etc. It makes it easier that way.

Anyway I would let it ride and check it in the AM to see what the levels are then. Have a nice night, and feel free to holler back with any questions you might have.