Massive Green Algae - No FC readings

[judilynn824]

I need some help I have a 24 ft above ground pool. I have been fighting a horrific algae bloom for 2 weeks now. I cannot maintain a fc reading despite massive applications of shock or bleach. I have been using test strips and all of my levels are in the normal range EXCEPT the fc. I know you need accurate readings and will post them later after getting results from the pool store. I have read the Defeating algae posts and have followed the instructions for determining shock levels needed using the bucket test. I've put in the amounts of bleach indicated, tested, added more bleach, tested again. I simply cannot get an FC reading - even within 20 minutes or so of adding huge amounts of bleach. Last night I put 23 96 oz 6% bleach in with little change today. My question is this: Is it better to add massive amounts at one time, or to add what is needed to bring it up to shock levels ONLY and keep adding over time?

 

[woodyp]

Not gonna be able to help much without a full set of test numbers, but you are correct. Add whatever "massive" amount of bleach is necessary at one time to bring your FC level to the shock value for your CYA level-------and HOLD it there. Test strips won't measure anything even close to the FC numbers required for shocking. Do yourself a big favor to make pool life easier and order one of the 2 test kits here. I honestly don't know how I'd run my pool without one.

 

[Butterfly]

Well, this sounds like ammonia.

Raise to shock level and keep it there. Test and add chlorine as often as you can back to shock level..

What is the CYA level? Give us test results and tell us how you got them.

Welcome to the forum

 

[duraleigh]

I simply cannot get an FC reading - even within 20 minutes or so of adding huge amounts of bleach. Last night I put 23 96 oz 6% bleach in with little change today.

That would indicate you used up 70ppm of bleach in 20 minutes. Something seems to be amiss. Ether your test strips are WORTHLESS (which is very possible) or the bleach is WORTHLESS or you have set a new worlds record for chlorine consumption.

If that much bleach made NO change whatsoever to the appearance of the water, I imagine you need to find another source of bleach.

Regardless, the only thing that will clear your pool correctly is chlorine and lots of it.

Pour a little (1 cup) of the clorox into a gallon jug and put the test strip in it. What do you get?

 

[taekwondodo]

I simply cannot get an FC reading - even within 20 minutes or so of adding huge amounts of bleach. Last night I put 23 96 oz 6% bleach in with little change today.

That would indicate you used up 70ppm of bleach in 20 minutes. Something seems to be amiss. Ether your test strips are WORTHLESS (which is very possible) or the bleach is WORTHLESS or you have set a new worlds record for chlorine consumption.

I have seen this happen on a few of the really bad green-to-cleans we have done, where after adding 20-30ppm of 12.5%, it's just plain "gone" 30-60 minutes later. I just keep "re-upping" to SC levels every hour or so. In two (very bad) cases in particular, I've had to do this 4-5 times before any FC level would measure. To make sure I wasn't going nuts, I did measure CCs, and was getting 5-10ppm of CC when the FC was zero an hour later...

But without the right test kit, you won't have the right info. The TFTest kit is the first "right tool" you need to get.

- Jeff

 

[judilynn824]

The pool does look some better this morning. Lots of little clumps of algae floating on the top - some green some gray. I just dipped all of that out, cleaned the cartridge, and am headed to the pool store for a reading. I live in Florida - it's hot and sunny today. I know you are supposed to put chems in at night, but I am going to lose ground if I don't keep adding all day. I have tested with the strips - in the pool and using the bucket test. All of my levels are in the normal range, except the fc which is dark purple within 10 mins or so of adding the bleach, but shows 0 fc after 30-45 minutes.


And, I must be getting there as the bucket test held a fc reading after the first step. Ya'll are awesome and this forum is so helpful.

 

[JasonLion]

With chlorine disappearing that quickly, adding more during the day is fine. Adding chlorine only in the evening makes much more of a difference if your FC level is more or less stable, because that is when you lose the most chlorine to sunlight. But with chlorine vanishing instantly, sunlight isn't really an issue.

Please post numbers for your test results. That will allow us to give you much more specific advice.

 

[duraleigh]

Well, if you have good Chlorine, you are obviously consuming more than I really ever thought possible. However, the procedure is the same and it sounds like you're doing exactly whats required. Adding chlorine constantly and cleaning your pool and you system to get out the solids and let the water flow. It'll all be worth it, Judylynn, just keep your diligence and you attitude up. It may get frustrating over the next couple of days but everyone here will help get it clean,

 

[Butterfly]

I recommend that you get one of the good test kits. See Test Kit Comparison in Pool School.

The TF100 is the best bang for the buck and my fav. The Taylor 2006 is good, too.
Link to TFTestkits.net in my sig.

This will put you in control of your pool - and will stop wasting your time driving back and forth to the pool store.......and getting incorrect and or inconsistent test reports, which only cause problems for you and your pool!

 

[taekwondodo]

With chlorine disappearing that quickly, adding more during the day is fine. Adding chlorine only in the evening makes much more of a difference if your FC level is more or less stable, because that is when you lose the most chlorine to sunlight. But with chlorine vanishing instantly, sunlight isn't really an issue.

Please post numbers for your test results. That will allow us to give you much more specific advice.

To further add to that... when the pool's that bad, sunlight won't penetrate through the "green"/"white" that far, so you'll lose most of it to the process (shock) itself, and you will lose very little to sunlight - until the pool is almost clear (and by then, you're almost done).

 

[chem geek]

That would indicate you used up 70ppm of bleach in 20 minutes.

This is certainly quite possible since that amount of chlorine would be needed if around 25-30 ppm CYA was degraded by bacteria to ammonia and the chlorine would react with ammonia in seconds to a minute -- it's very fast -- to produce monochoramine which would register as CC. It's only the partially oxidized CYA fragments (if any) that are somewhat slower to oxidize taking hours to a day or two.

 

[taekwondodo]

Not sure if I should add this to the thread - as it is self-serving... And may be broken off to another topic if necessary

I had at-least two cases this year alone where FC was gone in an hour - both very very green, and dirty pools.

One had about the same level of CYA (60ppm, according to an "uncontrolled" comment from the customer) that the customer added last fall, right after he drained and refilled it (because it had gotten green). The Other had zero CYA (had looked like crud all winter). Both took at-least 60ppm over three-four adds in several hours before I measured anything.

But I am interested - as a 25 year keeper (and once breeder) of tropical fish - on the ammonia comment. My "aquariust" experience tells me that decaying matter will degrade with some part forming NH3. You add that CYA will add to this giving us.

However, at some point shortly after the HClO is gone, biological nitrification will start to occur:
NH3 -> NO2 -> NO3: With NO3 being the final product. In some cases, as in reefing, there are purpose-built places where oxygen-deprived water allows an anaerobic process to start de-nitrification, which takes the NO3 to N.

Ammonia is normally (at least in an aquarium) one of those things you get when you first "start-up" a tank, because there is no bacterialogical activity when you start.

The "tank" will "spike" upwards or more of 10ppm while the aerobic bacteria start making a foothold and begin eating the NH3, with it reducing to unmeasurable levels in a few weeks as the biological nitrification process continues to accelerate (followed by a Nitrite/NO2 spike which also goes to zero).

Even in tanks where there is no active filter, this process will occur as the bacteria grows in the water and on the walls/piping/etc... e.g., a swimming pool (or cement pond, which I have next to my pool for my koi). No filter is required for the process to occur (but it, along with flow/circulating O2, does help).

So, there's a couple of places I am going with this...

1) How, in a gross/green pool, does the NH3/NH4+ converted from CYA, not also spike as NH3 and then be converted to NO3 (or reduced to N if O2 is lacking - and I've seen several pools that have enough muck on the bottom where anaerobic denitrification has started (black mud, smells like sulpher)) when/once the HLCO is gone, and biological activity gets started?

and

2) I'm going to start bringing my NH3/NH4+ test kit with me to all new customer prospects who have the green/gross pools.

The self-serving question: If I do get a measurable NH3/NH4+ reading - suggestions? I'd rather not go through 10 cases (40gal) of 12.5% before I get a reading... as it costs me a lot of time and chemicals with frequent return trips...

- Jeff

 

[chem geek]

Soil bacteria can convert CYA into ammonia though in doing so there may be incomplete breakdown products that do not register as CYA nor as ammonia and explains why the chlorine demand can be higher than the ammonia reading would predict on its own even in a clear pool. If algae then grows (or a whole lot of bacteria) then it is true that the nitrogen will get taken up into cells to build up cell material. After all, that is why the bacteria convert some organics into ammonia in the first place -- to continue the process to build up amino acids, proteins, DNA, etc. So in some pools that are let go there may be a drop in CYA but not have measurable ammonia because algae take it all up for their growth.

One thing to keep in mind is that the ammonia test kit doesn't only measure ammonia, but also measures monochloramine. So to if you have Combined Chlorine (CC) and if that is mostly monochloramine, then the ammonia test kit will read the ammonia level plus 1/5th the CC amount.

You can always estimate the total chlorine demand from all sources, not just ammonia, by doing a bucket test with pool water and knowing that 1/4 teaspoon of 6% bleach in 2 gallons is 10 ppm FC. If you have high chlorine demand, then the only alternative to oxidizing it, most inexpensively using chlorine, is to dilute the water or otherwise remove organic debris from it if possible (i.e. filtration/backwash/cleaning).

 

[taekwondodo]

Soil bacteria can convert CYA into ammonia though in doing so there may be incomplete breakdown products that do not register as CYA nor as ammonia and explains why the chlorine demand can be higher than the ammonia reading would predict on its own even in a clear pool. If algae then grows (or a whole lot of bacteria) then it is true that the nitrogen will get taken up into cells to build up cell material. After all, that is why the bacteria convert some organics into ammonia in the first place -- to continue the process to build up amino acids, proteins, DNA, etc. So in some pools that are let go there may be a drop in CYA but not have measurable ammonia because algae take it all up for their growth.

So, in these cases, there is no (or I should say, no-longer) ammonia - there is an organic load (i.e., algae) that have consumed the ammonia as food.

As an aside, I'm also "big" into aquatic plants, and we're carefully balancing NO3, P and K along with CO2 to grow plants and not algae. NH3 (mainly, as a by-product of aquatic respiration) is a preferred up-take of plants, but also of algae - whenever there is an excess of NH3, the plants and algae will consume it as fast as it is generated and the algae will really take that as an opportunity, where NO3 will be taken out of the water column more slowly and will actually be measurable. NO3 will also be consumed by algae, but it is by-far not the preferred source of N.

Also, any NH3 not taken up by the plants is quickly reduced by the biological nitrification process - so it is very rare in an established tank to have any measurable NH3, as it is consumed too quickly to accumulate (either by plants/algae, or bacteria - both of which are organic in nature).

One thing to keep in mind is that the ammonia test kit doesn't only measure ammonia, but also measures monochloramine. So to if you have Combined Chlorine (CC) and if that is mostly monochloramine, then the ammonia test kit will read the ammonia level plus 1/5th the CC amount.

Cheaper test kits this is true (the Aquarium Pharmaceuticals kit, for one... as well as a lot of pond kits). These use the salisalate method which includes monochloromines (why it's useless on city water where chloromine reducers are used). For a few dollars more, you can get the Nessler-based test kits which exclude monochloromines (Tetra-test, as an example - and what I use).

Since I have the NH3, NO2, NO3 and the equivalent of a TFTest kit, and for some reason, I've become the local "guy-to-call" on green pools - it won't cost me anything to take readings at the next several I have and we can see what's really going on.

After all, what we're really doing is taking an active biological eco-system (the "swamp" a pool has become) and turning it back into a "disinfected" pool...

- Jeff

 

[chem geek]

Cheaper test kits this is true (the Aquarium Pharmaceuticals kit, for one... as well as a lot of pond kits). These use the salisalate method which includes monochloromines (why it's useless on city water where chloromine reducers are used). For a few dollars more, you can get the Nessler-based test kits which exclude monochloromines (Tetra-test, as an example - and what I use).

Thanks for that tip. I didn't know those alternative test kits were available and yes, I was referring to the more common (and less expensive) salicylate tests found in most fish/pet/aquarium stores.

 

[Siamese]

It's seems like there are a lot of folks on the forum dealing with ammonia problems this year, myself included. Got me to thinking, could this be a possible way to lower a severely high CYA reading?

There's obviously some bad side effects, but could introducing the right CYA-eating bacteria to a pool be a possible solution vs a drain/refill or a RO treatment?

 

[taekwondodo]

It's seems like there are a lot of folks on the forum dealing with ammonia problems this year, myself included. Got me to thinking, could this be a possible way to lower a severely high CYA reading?

There's obviously some bad side effects, but could introducing the right CYA-eating bacteria to a pool be a possible solution vs a drain/refill or a RO treatment?

A backbone of TFP teaches is that testing is key: It is generally the very first question asked to every problem presented.

Without testing NH3, we are "assuming" that we are seeing a lot of ammonia in pools - saying that "it seems like there are a lot of folks on the forum dealing with ammonia problems this year" without actual testing is assumptive, and could be incorrect - with the potential of leading us down many wrong paths. It would be like me saying, "I put in 4 lbs of CYA a while back, so my level is 'x' ppm..." When we all know that without a current and correct test reading, it could be 10ppm, or 1000ppm.

My points in the prior posts is that NH3 (ammonia) in a biologically active environment (like an aquatic environment - which is much like a swampy pool) is difficult to sustain, as it gets reduced quickly to NO2 and NO3 - and in the right environments gets further reduced to N (if you smell rotten eggs, or see black-ish goo on the bottom - you've made it this far and have the entire "circle of life" for N).

Ammonia is toxic (to aquatic life) in measurable levels above 1ppm when the pH is greater than 7.0 (ammonia toxicity begins to exponentially increase once pH crosses 7.0), yet many of our "ponds" support pollywogs, frogs, insect life and insect nymphs - and our local authority throws mosquito fish into repo'ed homes with green pools, and these cousins of guppies breed/multiply by the thousands.

While the CYA breakdown is through NH3, in a biological active environment it is likely converted to harmless NO3 faster than it can be measured. IF it is converted to NO3 through this process, then most of the FC consumption is likely through the oxidation of organics, and not interaction with NH3 (although the reduction of CYA to NH3 also likely increases how large the organic load is, and how fast it grows).

I am in a somewhat unique position in that I have the test kits, and get quite a few clean-ups (there might be a few others on the board as well who are able to do this). Since I have the kits, I'm going to start testing for NH3 (and NO2/NO3) on most new pools we get that have been at 0 FC and starting to turn, or have already turned, into a biologically loaded organic mess.

Let's see what the data really shows...

- Jeff

p.s.: Richard, it also occurred to me that a Nessler kit should be fine - as long as we haven't started the SC process yet, and there is no measurable FC or CC.

 

[JasonLion]

There is no reliable way to get the CYA to disappear. It happens to some people, doesn't happen to others. If there was a reliable way to get it to happen that would be really wonderful.

 

[chem geek]

Jeff,

Yes, the standard (inexpensive) salicylate kit works fine if the FC and CC levels are 0 as a result (say, because chlorine hasn't been added yet). I think that's what you meant (not the Nessler test which measures ammonia directly). In fact, it even works fine when there is CC, but you need to subtract 1/5th the CC reading from the test result (assuming the CC is all monochloramine). If there is any FC, then there is no ammonia since it reacts in seconds to a minute or so (depending on CYA level) to form monochloramine.

Though algae and other organics react with chlorine, they do not do so as quickly as ammonia. So if you add chlorine and even 5 minutes later it's at 0 ppm and especially if you see the CC level rise, then it is most certainly ammonia in the pool (there are other chemicals that react quickly with chlorine, but wouldn't be found naturally in pools). See the summary post of my experience where the chlorine I added was rapidly consumed within an hour. Initially it was ammonia, but you can see that it took a lot more chlorine after the ammonia appeared to be gone. I suspect it was mostly partially decomposed CYA intermediates such as biuret and allophanate. What was interesting was that adding the chlorine didn't have very high CC when I next measured, but that may be because I measured after 1-2 hours instead of after a few minutes so the initially formed monochloramine could have been mostly oxidized by the chlorine.

Note that initially the rate of chlorine loss was at least 12.5 ppm FC in less than 1-2 hours (and probably a lot less -- perhaps minutes), but then once the chlorine started to somewhat hold, the rate of loss went to 3 ppm FC per hour and rapidly dropped from there as the water then started to clear up.

Anyway, it will be interesting to see what you find out in terms of ammonia readings, but just keep in mind that you may find large chlorine demand rapidly consumed even after ammonia readings have gone to zero.

Richard