Really need help. SWG seems to be working, but chlorine level zero.

Apr 24, 2013
17
Parma / Michigan
First, thank you for taking the time to help.
We have a problem. Although it appears our cell (TE-15) is working (1 year old cell), our chlorine level drops quickly to zero.
Here’s a little background.
Our instant salt reading is 3400.
Our pump runs 12 hours per day.
The cell reading: 26V 7A 82deg – No trouble light – set at 90 percent.
Stabilizer level 50
Alkalinity 136
PH 7.7
Saturation index 0.3
Last Monday, Aug 21 - Water seemed cloudy so we added 4 gallons of chlorine (12.5%)
We also added ½ gal muriatic acid.
We backwashed - DE filter pressure after backwash 24.
The next day, Aug 22 – the water looked crystal clear. (Thought we beat it)
Today, Aug 29 - our chlorine level is almost zero, water looks cloudy and backpressure is 32.
Really not sure how to proceed?
Could it be a filtration issue? We have model 4820 and use 6 lbs DE. How do we know if something is wrong?
Could it be the cell? How do we know it it actually creating chlorine?
Thanks for your help!!
 
When swg is on, do you see small bubbles from the return jets? (I think that is hydrogen, a byproduct of the chemical reaction that generates the chlorine) Bubbles would indicate chlorine is being generated.

Do you have one of the test kits recommended on this site? You need to do SLAM, per the docs on this site, regardless of SWG functionality, if you want to properly clear your water.
 
You mentioned your water got cloudy a few days and you added some chlorine to clear it up. That was the right start but I dont think you got it all
My money says you didnt.

Check behind your light also. Algae loves to hide in that place.

Recommend to do an OCLT (overnight chlorine loss test). Test water just as it gets dark.
test again the next morning. If you have more than 1 ppm chlorine loss, there is organics in the pool consuming the chlorine.

If this is the case, you need to to do a Full SLAM.
http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

When you finish the SLAM, you need to maintian your FC per recommended levels and maintain at least the minimum FC.
http://www.troublefreepool.com/content/134-recommended-levels

First, thank you for taking the time to help.
We have a problem. Although it appears our cell (TE-15) is working (1 year old cell), our chlorine level drops quickly to zero.
Here’s a little background.
Our instant salt reading is 3400.
Our pump runs 12 hours per day.
The cell reading: 26V 7A 82deg – No trouble light – set at 90 percent.
Stabilizer level 50
Alkalinity 136
PH 7.7
Saturation index 0.3
Last Monday, Aug 21 - Water seemed cloudy so we added 4 gallons of chlorine (12.5%)
We also added ½ gal muriatic acid.
We backwashed - DE filter pressure after backwash 24.
The next day, Aug 22 – the water looked crystal clear. (Thought we beat it)
Today, Aug 29 - our chlorine level is almost zero, water looks cloudy and backpressure is 32.
Really not sure how to proceed?
Could it be a filtration issue? We have model 4820 and use 6 lbs DE. How do we know if something is wrong?
Could it be the cell? How do we know it it actually creating chlorine?
Thanks for your help!!
 
Thanks for the reply.
I don’t remember seeing bubbles from our return jets, but I will check.
We have the large pool test kit (very nice). My wife is a pharmacist and enjoys the testing process.
Thank you for the advice – we will use the SLAM.

- - - Updated - - -

Divin Dave,
I agree, it looks like we still have an algae issue - apparently it’s harder to eliminate than we thought.
I never thought about algae hiding behind the light. Can we wipe out that area, or should we use another method?
OCLT sounds like a good idea, but that brings up another question – I personally do not like the dropper color test – it’s extremely subjective (probably because I work in engineering :) Where can we purchase a water sample test system similar to a pool store?
SLAM sounds like a great idea, but it’s a little confusing to a rookie. Where can I find a list of acronyms and definitions for TFP? For example – FC is easy, free chlorine, but what about FAS-DPD?

I am a little surprised by the FC levels required by SLAM – not saying they are wrong – but that sure seems like a ton of chlorine.

Also- thought I would mention - our auto cover is closed 90% of the time, allowing very little sunlight.

The auto cover retracts into a plastic tub, which can accumulate leaves and debris. I wonder if this could also be a source for algae? We plan to clean and disinfect just in case.

Is it safe to assume (I hate that word) that our SWG is working correctly unless we see a trouble light? Also, what is the optimum voltage, amperage and temperature readings?
Thanks again for your help!
 
Couple things....

If you have a TF100, your test kit is already way better that the pool store. We know strips are worthless. The fancy equipment the pool store uses is all designed to accurately and precisely measure......strips. Don't emulate the pool store, trust your testing.

Next, head to pool school to see all the acronyms (and pretty much everything else you want to know). Start with the link in my signature.

Our recommended FC levels are safe and appropriate, even at SLAM levels, because we do everything in accordance with the FC/CYA ratio (see pool school). The industry at large simply does not understand the relationship and why it works.

Finally, to test if your SWG is producing chlorine, with the pump and SWG on, take a water sample directly from the return, test it, and see what you get. However, I agree with the others that you likely have algae in the pool that isn't quite at levels that make it visible.
 
Smykowski,
So the equipment at a pool store accurately measure strips. What a bummer! I was really hoping for something more precise. From now on – I trust my own testing.
Pool school – I am on my way!
SLAM - FC/CYA ratio looks good to me. I was just pointing out – from a newbie perspective – that’s a lot of chlorine! :p
Just to clarify, do I take a water sample from the return line after it enters the pool, or before it enters the pool? If before - How?
Thanks again for the advice!
 
Auto-covers are a nice feature, but like anything else that comes into contact with your pool water, it needs to be cleaned and maintained on a regular basis. When rolled up, it is very easy for small amounts of water to become trapped in the cover and thereby be a perfect breeding ground for algae and bacteria.

Based on the other clues you have mentioned, I would say you that you definitely need to SLAM your pool. My SWG did something very similar - ran it 12+ hours/day at 90% and got barely any FC reading (<2ppm). My stabilizer was also out of whack (CYA >150ppm). Once I got my CYA to appropriate levels and SLAM'ed my pool, well now my SWG operates at 40% and I only run the pumps 7-8 hours/day.

Also, just a friendly heads-up, you need either a Taylor K-2006C or a TF-100 (XL option) to do pool water analysis. Since your wife is the pharmacist, she'll love it because it's all drop-based titration and color change tests....and it's WAY more accurate than the pool stores ever are.

Also, if a SLAM is in your future, research the best bleach prices in your area [$/(gal x %)], because a SLAM can go for several days and you will use A LOT of bleach in the beginning. My little SLAM clean-up job took 3 days to pass OCLT and all I had was very minor water cloudiness and the SWG issue I mentioned.
 
Hi Dave from Michigan,
Sorry so late getting back, but certainly others are capable and have chimed in as well. So I will keep it short and not repeat whats already been provided.

Just a quick message to address your comment about that being a lot of chlorine.

Most - (well all actually) new or novice pool owners who visit the forum, have yet to learn a lot of the science which drives the TFP recommendations for FC levels. I havent been around long myself, but I trust in the science even though most of it is way over my head.

You're right, it is a lot of chlorine but only in the context of not having any Cyanuaric Acid in the water. The
Big Picture must be realized. The FC recommendations for SLAM level as well as every day maintenance are based upon science. CYA is so important, it simply cannot be taken for granted or overlooked if you ever have intentions of having a troublefree pool. If anyone ever tells you differently, tell them to provide the scientific data to back up their claim.

The link below isnt intended for you to learn, or to understand *you have enough on your hands now* but if you do, then man, you are awesome! Working in enginnering though then perhaps you can relate to reliable data. :)

All of TFPC recommendations are based upon this same type of data, not just some "idea" or backyard trial and error method that happens to be successful now and then. TFPC method works - every time - if it is followed as its presented. This is just 1 example of why we trust the information available in Pool School and we all maintain our pools by these same recommendations.

http://www.troublefreepool.com/threads/558-Pool-Water-Chemistry

Good Luck,


Thanks for the reply.
I don’t remember seeing bubbles from our return jets, but I will check.
We have the large pool test kit (very nice). My wife is a pharmacist and enjoys the testing process.
Thank you for the advice – we will use the SLAM.

- - - Updated - - -

Divin Dave,
I agree, it looks like we still have an algae issue - apparently it’s harder to eliminate than we thought.
I never thought about algae hiding behind the light. Can we wipe out that area, or should we use another method?
OCLT sounds like a good idea, but that brings up another question – I personally do not like the dropper color test – it’s extremely subjective (probably because I work in engineering :) Where can we purchase a water sample test system similar to a pool store?
SLAM sounds like a great idea, but it’s a little confusing to a rookie. Where can I find a list of acronyms and definitions for TFP? For example – FC is easy, free chlorine, but what about FAS-DPD?

I am a little surprised by the FC levels required by SLAM – not saying they are wrong – but that sure seems like a ton of chlorine.

Also- thought I would mention - our auto cover is closed 90% of the time, allowing very little sunlight.

The auto cover retracts into a plastic tub, which can accumulate leaves and debris. I wonder if this could also be a source for algae? We plan to clean and disinfect just in case.

Is it safe to assume (I hate that word) that our SWG is working correctly unless we see a trouble light? Also, what is the optimum voltage, amperage and temperature readings?
Thanks again for your help!
 
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