Hit the Stabilizer Wall - High Stabilizer Levels Won't Let FC Kill Algae

[Jgrono]

I have been reading posts on this site for the last two years ever since I bought a house with a pool. The posts I have read have been so thorough, I have never even had to post a question here. There have been a few algae blooms in the pool, but I have cleared them up by vacuuming to waste, adding DE to the filter, and a lot of brushing. I have been a fan of the TFP method but haven't adopted all of it's parts completely, but have stopped using pool shock, algaecide, and everything else except for chlorine tabs for the last 6 months... I figured chlorine tabs are easy to store and use...

A few weeks ago I bought some 8.6% Clorox from Sam's "in case" I wanted to shock the pool. Well coincidentally, it looks like I finally hit the point where I have too much CYA in the pool from stabilized pucks and am quitting the chlorine pucks.

I haven't had any major chemistry problems, and have done my own testing with a PAP 5-Way kit, (never had a reason to buy the TF100) and once in awhile I have them test my water, basically just to make me feel good because they always say the water is inline. I save all the printouts that they have given me. Sometime ago, I got a free pack of 6-way test strips but never even opened the package because I figured they were about useless.

There was a pretty big algae bloom that I have been fighting for about a week and started using the test strips as a quick test in between when I am using the 5-way. The test strips had a CYA test, which my cheap 5-way kit does not, and I noticed that the stabilizer was showing high. I looked back on all my PAP printouts and noticed that every time I have had my water tested at PAP for the last 2 years, the stabilzer level ON THE PRINTOUT has been exactly the same - 100 ppm. Since it never changed according to them and haven't had any problems, I never really cared to test for it.

I haven't had to really consider CYA since during the summer it rains a lot in FL and I backwash often. Since I now know I have too much stabilizer, to correct the CYA level, first, I removed all the tabs that were in the pool and bleach shocked the pool. Since the algae didn't seem to be dying, I drained some water, added fresh water and shocked with bleach. My CYA level is between 150-200 ppm. (I know, I know, TF100 test kit.)My TC level now is about 8 ppm (I know, I know, TF100 test kit.) and I really don't want to keep adding bleach if I have to keep draining water to get rid of the stabilizer. I am thinking the easiest way is to drain some everyday, then add more water, then keep draining until the stabilizer level comes down and the FC level is enough to kill the algae. I am going to continue to do this until I get the algae cleared. Does this seem like the easiest way?

I did not post my exact numbers because I know that responses are going to say to get a better test kit, but I don't have the test kit right now and once my stabilizer levels drop enough, I should start noticing that the FC level is high enough to start killing algae, right?

I do not think this is mustard algae, but a result of me pressure washing the pool deck. Usually after pressure washing the pool deck, I have an algae bloom.

I am now suspect of the testing methods that PAP uses to test for stabilzer. Does the test they run max out at 100 ppm? Or do they only enter a max value of 100 regardless of what the test results are?

Sorry if this post seems rambling! Any responses are welcome! I now see the reason for doing more than TC, pH, TA, and Acid Demand tests... If PAP tests showed that my stabilizer levels ever changed, I would have started testing for it a long time ago, but I trusted them just enough to make me not think about testing for it myself.

 

[jblizzle]

Welcome to TFP!!!

Your reluctance to invest in one of the recommended test kits has now come back to bite you. The CYA test does in fact usually max out at 100ppm ... so it could very well be WAY above that.

To clear up algae, you need to follow the ShockLevelAndMAINTAIN Process which it does not sound like you have ever done. You have to maintain adequate FC levels which are a function of your CYA level, see the FC/CYA Chart, I feel like maybe you are missing that fundamental understanding.

Do yourself a favor, stop guessing and invest in the TF-100 with XL option (since you need to SLAM).

 

[Jgrono]

I just ran both test kits that I have:

6-way Strips:
Total Hardness: 250 ppm
TC: 3-10 ppm
FC:3-10 ppm
pH: 7.2-7.8
TA: 120 ppm
Stabilizer: 100-150

5-Way PAP Kit:
TC: much greater than 5 ppm
pH: 7.6
TA: 80 ppm

During the last few days, I have used the Pool Math page for the amounts of bleach to add.

I was really conservative on the ranges for both test I did, and left the ranges for the strip test large.

 

[Jgrono]

JBlizzle,

Thanks for the quick reply. I have seen that chart and that is what I started doing, but I think it is a waste of bleach if I raise the FC up to the CYA level, because I am trying to bring my CYA level way down, ideally to 30 ppm. Right now, I am just trying to lower that stabilizer level. I am not trying to use a bandaid to clear up the pool, which I would be doing if I added enough chlorine to get a 38 PPM FC level with 100 CYA level. My CYA level is probably higher than 100 anyway.

If all I cared about was clearing up the algae, I could use the algaecide that temporarily bypasses the CYA level. That's probably what the pool store would try to sell me.

If I am missing a fundamental understanding, let me know, but I think you are misunderstanding what I am trying to do. I am trying to bring the CYA level down. Of course, while doing that I still am watching the FC level.

As long as I can get the CYA to 30 PPM, I have to bring the shock FC to 12. 12 takes a lot less bleach than 39+, and as long as I am not using pucks the CYA level shouldn't climb unless I add something that will increase it.

If I leave the FC level above 8 until the CYA comes down, then I will nuke it with bleach when I am done draining water from the pool.

Right now, I have to guess since I cant speed up shipping time.

 

[Jgrono]

Allright, according to Pool Math, I would have to replace 80% of the water to bring down my CYA. It looks like I may have to use a band-aid for this. If anyone has any other suggestions, please let me know.

Right now, the pH is 7.6, TA is 80 ppm, looks like I am going to have a full recycling bin of bleach containers... hopefully, I can resist the urge to go to the pool store for some algaecide that will bypass the stabilizer until the outbreak is gone.

 

[jblizzle]

Algaecide does very little to clear up algae, it is used as a preventative, but using chlorine is cheaper and easier for prevention and killing the green pool.

We do not recommend "nuking" the pool. Follow the SLAM process.

There is no band-aid. You need to replace a LOT of water to lower the CYA level and then you need to use a good test kit to SLAM the pool.

 

[swoopman]

If you're going to use a band-aid approach then use the knowledge you gain from this site and choose wisely - for example don't use a copper algaecide that could compound your problems and don't use a band-aid that adds to your stabilizer problem. Don't know what the pool looks like except you state you have an algae bloom so bleach might be the best band-aid for a few days until your TF-100 arrives. Then you can get accurate measurements and formulate a game plan based on really knowing what's going on with the water.

 

[Jgrono]

Thanks for your replies. I can't believe the day that I finally joined this site I am actually thinking about going to the pool store. It looks I am going to get some sodium bromide to kill the algae, and over time I am going to have to lower my CYA. The pool stays pretty stable over the winter, so as a worst case scenario. I can wait until it starts raining everyday here to change out the water and lower the CYA.

I wouldn't ever use copper for the same reason that I wouldn't add a pool heater... metal in water is no good.

I figured out it is still cheaper to buy the algaecide than the amount of bleach it would take to SLAM the pool. That shock level of chlorine needed scares me too. I think I am going to bring a water sample to them just for some giggles.

The pool doesn't actually look that bad, but I usually keep it clear enough so that at night with an underwater light on and no water circulation, it looks like there is no water in the pool.

 

[chem geek]

If you get sodium bromide then you will be turning your pool into a bromine pool and depending on how much you use it could stay that way for quite some time.

Why don't you just start doing partial drain/refills? Since you have to do that at some point anyway, just start doing that now. If the pool doesn't look that bad, then just keep the algae somewhat at bay by maintaining a higher FC level rather than doing a full SLAM. The risk is that things could get worse, but as your CYA level drops from the partial drain/refills, the same FC level will be more effective and then you'll be able to SLAM without extraordinary amounts of chlorine.

The precipitation in Gainesville, FL is substantial year-round at 2-7" or a total of 50" per year. So if instead of just having this refill evaporation you were to replace more of your water, you could dilute it faster. This is why even using Trichlor it took some time for the CYA to build up because you had at least some dilution though obviously not enough.

By the way, just increasing the ranges for the test strip doesn't mean the actual amount is in the range you gave. Test strips can be completely wrong -- not just broader in their interpretation. I don't understand your hesitation towards getting a proper test kit. Didn't you save enough money from not having to use shock and algaecide and other pool store products to be able to afford a proper test kit?

 

[Jgrono]

Why don't you just start doing partial drain/refills? Since you have to do that at some point anyway, just start doing that now. If the pool doesn't look that bad, then just keep the algae somewhat at bay by maintaining a higher FC level rather than doing a full SLAM. The risk is that things could get worse, but as your CYA level drops from the partial drain/refills, the same FC level will be more effective and then you'll be able to SLAM without extraordinary amounts of chlorine.

Chem Geek,

That's exactly what I was explaining in my first post. At least I was thinking along the right lines. I think that's why JB said I didn't understand the concept. Pool Math told me I need to exchange 80% of the pool water, so I am going to just live with the CYA levels, and keep doing partial drains and refills. Eventually, I will get it there. I was reading some posts about how CYA dissipates over time, and I am hoping it goes as fast as some people think. The pool must be losing CYA somehow because it was been on stabilized chlorine tabs for at least 4 years, since the PO used them too.

FWIW, I had PAP test my water. All of the results that he got were exactly what I did except for the stabilizer test... maybe they are using the same cheap-o test that I have. Their Cl test maxes out at 5 ppm. When he told me the stabilizer was at 100 ppm, I started asking him the range of that test, he said it only goes to 100 ppm, but that he could dilute the sample and try again. He did that, but after I left the store I looked on the printout... it still said 100 ppm. I am not sure if they even change that value in the computer.

FC:5 ppm
pH: 7.6
TA: 80 ppm
CH: 275 ppm
Stabilizer: 100 ppm
TDS: 600 ppm

So even if it takes a few minutes, it's really not worth it to have them check the water at all.

And as for my hesitation in getting a test kit, I have never had a problem, so why would I buy another kit? Since I planned on going all bleach after my tabs ran out anyway, I was already planning on getting a TF100. I got the other kit as a present, so I didn't have a choice.

I have saved a lot of money in the last year. So you're right, I have no excuse not to give a little back to the pool.

It is too cold to swim here now, so nobody will be using the pool anyway.

 

[tim5055]

FWIW, I had PAP test my water. All of the results that he got were exactly what I did except for the stabilizer test... maybe they are using the same cheap-o test that I have. Their Cl test maxes out at 5 ppm. When he told me the stabilizer was at 100 ppm, I started asking him the range of that test, he said it only goes to 100 ppm, but that he could dilute the sample and try again. He did that, but after I left the store I looked on the printout... it still said 100 ppm. I am not sure if they even change that value in the computer.

I have saved a lot of money in the last year. So you're right, I have no excuse not to give a little back to the pool.

You say you have been reading for a couple of years, so you have probably seen that not much credence is given to pool store testing. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. The PAP you used maxes their Fc test at 5 and CYA at 100.

You say he did a diluted test and still came up with 100, so sorry to say you are probably north of 200. I understand, I've been there.

Sorry to sound harsh, but you have been doing the least you can do to maintain the pool all along - time to pay the piper.

if you have algae the only way to fix it without causing additional problems down the road is to follow the SLAM Process to the end. Anything else is jsut a band-aid and again is going to cause more/bigger problems later.

Jason has been around here enough to understand what you were saying. You were saying you wanted a quick fix, but there isn't one.

In the real word you have two choices.

Do the water exchange to get the CYA down and then SLAM or
Don't do the water exchange and SLAM at grossly high/expensive chlorine levels.

Once you get your TF100 you need to do your own diluted CYA test. While the full instructions are in the Pool School, here is the short version. Mix 50% pool water with 50% tap water. Use this mixed sample as your test water. If still at a 100 you will need to dilute more. Here is a great chart by JamesW to explain dilution rates and what you multiply the results by to get an approximation of your CYA level.

Pool water......Tap or distilled water.........Multiply result by

....1...................1................................2
....1...................2................................3
....1...................4................................5

 

[Jgrono]

Tim,

You aren't sounding harsh because I already know what my situation is. Chem Geek is the only one who actually put some common sense into his post and considered the situation. I already knew I had to get my CYA level down, but I think you guys are missing the point that the SLAM level may kill the algae, it just doesn't make sense to add that much bleach. The other option is to drain most of the pool, which is only slightly better than adding bottle after bottle of liquid chlorine.The real fix is to drain the pool to get rid of the CYA level. I didn't know of a quick fix, and was hoping that someone on here did, and I ended up answering my own question!

All you did was repeat what I said, I already posted the PAP limits, and never said the stabilizer was at 100. I only said that the printout will probably always say 100 for stabilizer even though the employee ran the test and got a different number.

There is no paying of any piper, the pool is in better shape than when I got it, and has been that way for 2 years!

The funny thing is that a TF100 kit is only going to tell me accurately how crazy out of range my CYA is. My CYA level isn't even on the chart... I knew that before I started this thread.

Anyway, thank you all for your replies, but there are already great links on this site to Pool School and the SLAM method. It seems like you guys would have something better to do than just copy and paste that info into the forums and then make yourself feel good by saying that no one understands as well as you do. If JB looked at the SLAM chart before he posted a link... Maybe after I get my CYA down I can post back here to people that I have been there and I can tell them they don't understand...

Thanks again ChemGeek. No one else has to bother responding on my behalf because it looks like I will just stick to the Pool Math page from now on.

 

[jblizzle]

And as for my hesitation in getting a test kit, I have never had a problem, so why would I buy another kit?

Doesn't the fact that you have said you have fought algae in the past and now have a bloom indicate that you do in fact have a problem?

Until you have reliable test results and commit to a plan, you really are kind of throwing money away and still apparently searching for a magic potion if you think bromide is the solution.

BTW, the concept that I think you were misunderstanding is how to have prevented algae in the first place. If you "knew" the CYA was up around 200ppm, were you always maintaining your FC >> 14ppm? Doubt it since you were relying on pucks and your test does not read above 5ppm.

Sorry I was not able to read your mind and know what you know ... and with that ... Good luck :gone:

 

[pooladdict]

Neat door Jason

 

[Jgrono]

Doesn't the fact that you have said you have fought algae in the past and now have a bloom indicate that you do in fact have a problem?

Until you have reliable test results and commit to a plan, you really are kind of throwing money away and still apparently searching for a magic potion if you think bromide is the solution.

BTW, the concept that I think you were misunderstanding is how to have prevented algae in the first place. If you "knew" the CYA was up around 200ppm, were you always maintaining your FC >> 14ppm? Doubt it since you were relying on pucks and your test does not read above 5ppm.

Sorry I was not able to read your mind and know what you know ... and with that ... Good luck :gone:

I should have just closed my browser window after my last post so I wouldn't have wanted to respond... That's the point, why would anyone try to maintain a pool with too much stabilizer? The stabilizer level has to be reduced. That's why ChemGeek was talking about rainfall and getting the level low enough to actually slam the pool.

There is no magic cure, the only cure is to get rid of the CYA. That's probably why there aren't shock levels higher than 100 on the SLAM chart. If you guys actually read my previous posts, instead of attacking me about testing and not knowing how to slam, you would have read that I usually have an algae bloom after I pressure wash the pool deck. I don't want to have to deal with this problem again... in my first post I wrote that I was no longer using tabs, and I had previously planned on not using them anymore. I was just trying to use up what I still have. That sounds like a plan to me.

Sodium Bromide is not a solution, it will clear up the pool and buy me time so that I can bring the CYA down by slowly draining and refilling.

Really, I should have been monitoring CYA all along and avoided this problem. There's nothing I can do about that now.

You don't have to be a mind reader to see in my first post where I posted a CYA of 150-200 ppm. You then referred me to the slam link... Try to figure out how much liquid chlorine you need at that level.

I am not trying to discourage anyone from trying to help somebody who posts here, but if you answer a post without actually reading the details it doesn't do anyone any good. I guess I am guilty of the same thing since I never read that PAP CYA test maxes out at 100 ppm.

If you had responded to my post, "You're an idiot, you should have been monitoring your CYA all along it's way too high, now you have to get rid of it before you can slam it," I would have agreed with you.

Correct me if I am wrong on anything. I had a problem, and instead of helping me work through it, you were telling me what I should do after my problem gets fixed. That's not very helpful. I have seen it on here a bunch of times where people just keep putting in their 2 cents without actually wanting to help.

 

[JasonLion]

Sodium Bromide is it's self a problem. Yes, it might clear up the pool, then again it might not. There will also be side effects, often noticeable but minor, occasionally major. On average it causes more trouble than it solves. Who knows, maybe you will get lucky and it will clear up the pool and have few side effects, but the odds aren't really in your favor if you try that.

The solution that will solve the problem, cost the least, and have the fewest risks is to replace water to get the CYA level down. Sooner, rather than later. There are other things you can try, but they all cost more, require more work, and have lower odds of success.

 

[chem geek]

The pool must be losing CYA somehow because it was been on stabilized chlorine tabs for at least 4 years, since the PO used them too.

Being in Florida you may keep your pool open year-round, maintained with chlorine even if you don't use it. If the 50" per year of rain were diluting the pool water and if your average pool depth is 4.5 feet (52"), then assuming continual water replacement from such rain this is a 62% dilution of the water on an annual basis. If you have 1 ppm FC per day chlorine usage because you haven't been keeping your FC/CYA ratio up, then the daily average dilution (ignoring other dilution possibilities such as backwashing a sand filter or splash-out and carry-out) would be 0.26% so the steady-state CYA level would be 1*0.61 = CYA * 0.0026 so CYA = 234 ppm. Chlorine oxidation of CYA is slow and perhaps only around 2 ppm FC per month so it's mostly the rain dilution that accounts for somewhat limiting the CYA buildup.

As Jason noted, the sodium bromide will have side effects since a bromine pool tends to lose bromine faster from the UV in sunlight than chlorine (with CYA). The worst part is that it isn't easily reversible -- there is nothing that can remove the bromide from the water and any oxidizer will turn such bromide into bromine. Bromine will very slowly outgas from the pool and that is the only way it will go away other than water dilution.

The purpose of having a proper test kit is not to only have one when one has problems, but rather to have accurate information to prevent problems in the first place.

 

[Tepelus]

I would use 4-6 ppm bromine from sodium bromide without hesitation. It is not affected by high CYA levels and will be diluted together with CYA when and if decide to drain and refill. Some chlorine will be used to convert bromide to bromine, but if you add enough chlorine you will have a mixture. If you use it only once, and solve the problem now, you must remember next year that you have to dilute with fresh water in order to reduce the CYA level. Bromine will slowly outgas and will be diluted as well, so you will have a fresh start next year. In the competition against algae the pool opaque cover is your best friend. It will starve the algae of sunlight. Algae growth rate is proportional with the amount of light that is hitting the pool water. The pool cover will reduce the amount of chlorine or bromine that is lost due sunlight and out gassing.

 

[Isaac-1]

I am going to ask a question and make a suggestion or two, first why are you resistant to biting the bullet and doing a series of partial drain / refills now? You could have everything done within a week, and stop all this algae headache, being in Gainsville if you don't have a heater your swim season is probably over with for the year since you have a low in the 30's in the forecast for this weekend. Of course you will need a good test kit with a CYA test to know when you have diluted the water enough, and once you get all this in line have you considered switching to an SWG (Saltwater chlorine generator) if you don't like the idea of carrying lots of jugs of bleach? The long term cost of operation of an SWG is comparable with traditional chlorine methods, you just have a bigger upfront investment.

Ike

 

[singingpond]

...
Sorry if this post seems rambling! Any responses are welcome!...

Couldn't help noticing this in the very first post. Kind of amusing.

Honestly, if you were a little more patient and polite with responses that you don't think are on target, and just refocus your question, if necessary, you'll get a lot more useful feedback from the experts who freely volunteer their time on this site.