Opened Green Yet Again and Don't Want to Spend $$$$ on Shock

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BabsNMK

Well-known member
May 19, 2018
69
Cranbury, NJ
Hi. I found this forum last year after spending almost $1000 on getting my pool clear after opening. I vowed never to do it again so this year when we opened green I ordered a Taylor test kit and here I am. I'll admit this is all very confusing because chemistry is not my strong suit but I manage most of my pool and my engineer husband is leaving me to it.

We opened last Friday very green as we did last year (probably due to a mesh cover?). After the company opened I added a bunch of shock and algecide. The color has now improved to an aqua but there's a ton of dead algae (I can't seem to vacuum enough out) and very cloudy. As of today I can kind of see the bottom. I brought the water to my pool store and their recommendation is to drain 12 inches below the skimmer and refil and then add 40 POUNDS!!!!! of shock. I refuse to do that again.

The test kit came tonight and here are my numbers:

FC 2ppm
CC 2.5 ppm
PH 7.5
ALK 230
CH 180
CYA 100

I've read through the Pool School files but I'm still really confused (again I'm a communications major not a chemist). Please help! I think I probably need to SLAM? But not sure how to start that despite reading about SLAM at least 10 times. So if someone could spell it out for me I'd greatly appreciate it.
 
Hi, welcome to TFP! Your pool store was partially right. You do need to do a partial drain and refill to get the CYA number down. Vacuum the pool to waste to remove what dead algae you have, then drain the pool down about 2/3 and refill. That should lower the CYA to between 30-40 ppm. Then you will be ready to slam the pool.

For the slam, you will need to use liquid chlorine. Liquid chlorine doesn't contain CYA like dry chlorines (dichlors and trichlors) do. You can either buy liquid pool chlorine or you can use regular, unscented household bleach. If you use bleach make sure it doesn't use chloromax technology or anything that is supposed to repel dirt. To conduct a slam test the pool for FC, pH, and CYA. Adjust pH if needed and then use the [FC/CYA][/FC/CYA] chart to determine what your target level is for the slam, then use PoolMath to determine how much chlorine to add to reach your slam target level. Test FC and CC every couple of hours and raise the FC back to target level as needed. Keep the pump running 24/7 during the course of the slam. Keep an eye on the filter pressure and backwash the filter when the pressure rises 20% over clean pressure. If you are not sure what your clean pressure is, backwash the filter before starting the slam and record the clean pressure. Brush the pool daily during the slam.
 
Ok the principles of SLAMing a pool is taking the chlorine levels higher than maintenance levels to sanitize.

Shock is not a product and it is not technically the packets of granules that you throw in your pool which is calcium hypochlorite which raises your calcium hardness CH and also raises your free chlorine. FC and CYA. What shocking a pool technically consist of is again raising the free chlorine or FC to heightened levels to sanitize.

According to your test numbers you're cya or cyanuric acid is way too high.

My first question is do you have a saltwater chlorinator. Or a non salt water chlorinator system?

Typically a non salt water chlorinated system you want the cya range to be between 30 and 50 PPM to utilize the chlorine propetly. Once certain levels of cyanuric acid are in the pool, the only way to remove it is to drain water and refill it with fresh water.

The cya also known as conditioner has a interrelationship with the chlorine, the CYA buffers the Free Chlorine FC depletion. Or usage

Pool School - Chlorine / CYA Chart

If you're cya is below 30 PPM the sunlight will burn up to chlorine quickly. If it is again above 50 ppm for a non salt water pool. It will take more heightened levels of chlorine to sanitize. Search for cya chart on tfp. It will give you the proper chlorine amounts to ratio for cya.

First thing you need to do is procure test kit preferably Taylor K - 2006 or TFT - 100.

Please again review Pool School.
Your first objective is to lower the cya within the specified range, do a partial drain, and refil, test it, get your number to between 30-50 30 being preferable. Then add the appropriate amount of chlorine for that cya number. If you use the pool calculator you can input all these numbers into it, it will detect it where you can enter the numbers at current, and then enter the numbers into the next field for your target.

So for example if your chlorine levels are currently 2 FC, and you want to SLAM the pool to sanitize the algae, and once you get your CYA to lets say 40 ppm for arguments sake, to shock your pool, you would have to maintain shock levels 16 FC at all times, until all 3 criteria of OCLT or over night chlorine loss test are passed. The 3 criteria is water is clear, OCLT is no more loss than FC 1-2 ppm in a 24 he period, and CC or combined chlorine is .5 ppm or lower. combined chlorine is a chlorine as being utilized to sanitize your pool, that is working on the algae or any other organics in the pool.

Get as much debris out of the pool with the leaf net as possible, drag the floor blindly if you have to.

SLAM stands for Shock Level Adjust Maintain. For now do not use any shock packets whatsoever or chlorinated tablets also known as TriChlor Tabs. Only strictly use liquid chlorine pool chlorine or liquid bleach denoted at 6% or 8.25 % percent if you can find it. Or you can just get the liquid pool chlorine at 10 to 12%. Important note make sure the bottle says sodium hypochlorite. You only want to use sodium hypochlorite bleach not dichlor or trichlor, as dichlor and trichlor will raise your cya levels significantly

Any further questions on the process feel free to leave a message I'll get back to you
 
if you are doing a partial drain, then re-fill... the CYA should register almost immediately once the old, and fresh water have blended fully... 1/2hr with the pump running on recirculate/bypass will do it.
 
Another recommendation is to update your signature a little further and elaborate on the equipment that you have so we can assist you further. Take a look at your pool pump get the horsepower amount the make and model. Sanitizing the water is going to be your most important and first step in clearing the green out of your pool.
If you maintain your slam levels properly for a certain period of time and should change the water from green to aqua, to cloudy blue. Your filtration system is what's going to get all the fine algae out of the pool and enhance your water clarity, which is the later and second step to this process. Make sure to brush everywhere all over the pool everyday. Algae has a way of hiding behind things like pool ladders, lights main drains, Etc. Algae forms a slippery biofilm and you have to brush it sanitize it and filter and out of your pool.
 
Welcome to TFP....Thanks for posting your reading... It looks like you going to have to SLAM your pool now. These are the steps I follow...I keep notes of what I need to do. Tend to forget a lot.LOL

You got the test kit which is GREAT.
I don't know how your pool looks like, but if you have debris (etc), you should clear you pool of debris using pool tools such as a brush, vacuum, pool net , etc. If your pool is really dirty, it is recommended that you vacuum to waste to avoid clogging up your filter.
Your pH looks good.
Your CYA is pretty high. Like zea said, drain your pool down about 2/3 and refill. Retest for CYA and once it's at 30-40, you can start the SLAM process.
When your CYA gets within range, use the this link Pool School - Chlorine / CYA Chart (as explained previously) to determine the shock level you’ll need to SLAM your pool. For instance, if your CYA is 30 you will need to bring your FC level to a 12, thus starting the process of SLAMing your pool. Use PoolMath to determine how much chlorine you’ll need to reach shock level. Maintain your shock level… at the start of SLAM, chlorine may decrease rapidly as algae is being killed off. This is the reason why, at the start of the SLAM process, it is imperative that you make sure to test for FC every couple of hours and maintain the shock level by adding the correct amount of chlorine (PoolMath) when necessary. Once algae is being killed off, the chlorine will not deplete as fast as it used to and you’ll not need to test so often.
Make sure you leave you pump running 24/7 while SLAMing your pool (proper circulation/filtration of the pool water is recommended).
Continue vacuuming and brushing pool each day while in SLAM mood.
Once pool is clear, its time to perform the following Overnight FC Loss Test (OCLT)



BabsNMK said:
Hi. I found this forum last year after spending almost $1000 on getting my pool clear after opening. I vowed never to do it again so this year when we opened green I ordered a Taylor test kit and here I am. I'll admit this is all very confusing because chemistry is not my strong suit but I manage most of my pool and my engineer husband is leaving me to it.

We opened last Friday very green as we did last year (probably due to a mesh cover?). After the company opened I added a bunch of shock and algecide. The color has now improved to an aqua but there's a ton of dead algae (I can't seem to vacuum enough out) and very cloudy. As of today I can kind of see the bottom. I brought the water to my pool store and their recommendation is to drain 12 inches below the skimmer and refil and then add 40 POUNDS!!!!! of shock. I refuse to do that again.

The test kit came tonight and here are my numbers:

FC 2ppm
CC 2.5 ppm
PH 7.5
ALK 230
CH 180
CYA 100

I've read through the Pool School files but I'm still really confused (again I'm a communications major not a chemist). Please help! I think I probably need to SLAM? But not sure how to start that despite reading about SLAM at least 10 times. So if someone could spell it out for me I'd greatly appreciate it.
Click to expand...
 
I updated the signature. Last night I was in such a rush to post this and wasn’t near the pool so thanks for the reminder!

Also we don’t have a floor drain so essentially the only way I can drain is u til we get below the skimmer because at that point there’s no other way to suck the water out. What do people do here? Attach a tube somehow and drain that way?

last question and I’ll get started. Our filter doesn’t have a waste option but my husband said to vacuum to waste I can just vacuum in the rinse mode. That doesn’t sound right to me (and he knows very little about pools). I normally
vacuum with the filter function and then just empty the secondary basket at the base of the filter. Is that correct?
 
cfherrman said:
Vac to rinse will work but will require backwashes as you are filtering the water your tossing

Have you done a diluted cya test first? You need a idea on how high your cya is, the test maxxes at 100 so it could be 150, 190, 250....

Step 8 on cya test in extend test directions

ABCs of Pool Water Chemistry
Click to expand...
I looked in the book that came with the kit and don’t see extend test. I did the CYA test on the back of the kit and then don’t see anything in the booklet.—never mind I saw it’s under chlorine stabilization.

i did remember to use the sump pump to drain so that’s what’s happening now. I forgot about that.
 

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To do the diluted CYA test, mix pool water with tap water, 50-50 ratio. Then use the diluted sample to fill bottle to bottom of label, and so on.

Multiply result by 2.
 
kellyfair said:
To do the diluted CYA test, mix pool water with tap water, 50-50 ratio. Then use the diluted sample to fill bottle to bottom of label, and so on.

Multiply result by 2.
Click to expand...

Ok so that’s what I did. The first time it reached 100 when I couldn’t see the black dot. The 50/50 test I added the mix into the tube and I could see the dot the entire time. It was never cloudy enough to make the dot invisible using the 50/50 mix. Does that make sense? The sample reached all the way to the 30ppm mark and I could still see.
 
BabsNMK said:
Ok so that’s what I did. The first time it reached 100 when I couldn’t see the black dot. The 50/50 test I added the mix into the tube and I could see the dot the entire time. It was never cloudy enough to make the dot invisible using the 50/50 mix. Does that make sense? The sample reached all the way to the 30ppm mark and I could still see.
Click to expand...

No, it doesn’t make sense. If your CYA in the first test was really 100 or more, the diluted test should have given you at least 50, before multiplying.
 

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