dark green pool - how do I clean it??

[Randy n Mary]

I have read most all the post on here to try and get my pool back to its orignal state. I have seen so far that bleach is the best and cheapest way to go. I have a 18 foot above ground pool, I have used shock after shock and within days the pool is back to the nasty green. I'm trying the bleach now and will post in a day or so to let you know how it works out. I do know DON'T MIX the bleach and shock together. The shock will just elimanate the bleach. Learned that the hard way already. I want to say thank you to everyone who has posted on here and will try different things to help us all take the green out of the pool and leave the green in our pocket where it is best at.
Thanks, Randy...

[chem geek]

Read Defeating Algae and how to Shock Your Pool. If by "shock" you mean stabilized chlorine products such as Dichlor or Trichlor, they do not eliminate chlorine, but they add Cyanuric Acid (CYA) that as it gets higher will reduce chlorine's effectiveness.

[runderwo]

Hi this is rob.
In looking over this forum i can't find the answer to my pool. I've tried all the advice given but with no luck. Here is my short version of the story. I got married and while gone at the wedding/honeymoon, my pump decided to no longer work. So i went 3 weeks of a still pool. When i came back the pool was an awful green color. We changed our pump and put in a chlorine generator (saltwater).
We shocked it with bioguard shock (14 bags) and ran the pump on super chlorinate 24/7. In that time we dumped in 17 bags of pool salt. After that we put in Banish an algae KILLER and then flocced it. It set for 14 hours on still water then vacuumed to waste. Then put in another bottle of banish.
Water still didn't look good. So, we put in 2 bottles of flocc, waited about 27 hours, vacuumed to waste, twice, and still no change. My pool guy is stumped and is literally giving me bottles of chemicals for free to see if anything works. I put in an AMS algae KILLER of 7% copper, but still nothing and put in sparkle up to help the filter, but still nothing.
I read about bleach, and put in 6 bottles each a little over a gallon at night last night, and it's still not clear this morning. We have little to no visibility, the color is a greenish blue and our ratings are near perfect on our pool guys water samples. FC at 3 (highest was at 9.) 25,000 pool with 6 bottles of bleach should have brought our FC crazy high plus the generator was on shock mode. CYA at 40 PH 7.4.
I NEED HELP nobody knows whats going on with our pool and im about to vacuum to waste again and will check this tonight hopefully with answers and suggestions! I feel like i've tried everything.

[chem geek]

If your bleach bottles were standard size, then they were 3/4-gallon (96 fluid ounces). I hope you used either 6% Clorox Regular or off-brand Ultra bleach that is usually 6%. Otherwise, if you used an off-brand regular bleach it was probably <3% in strength. 6 3/4-gallon bottles of 6% bleach in 25,000 gallons would only raise the FC by 11 ppm -- not "crazy high". Also, shocking is a process, not a one-time event.

Was the BioGuard® shock that you used BioGuard® Smart Shock®? As shown in this MSDS, this product is 63% Dichlor and also has copper in it. For every 10 ppm FC added by Dichlor, it also increases your Cyanuric Acid (CYA) by 9 ppm. The bags come in 1 pound and 2 pound versions. If I assume you used 1 pound bags, then 14 bags of 63% Dichlor in 25,000 gallons would raise the FC by 23 ppm, but would also raise the CYA by 21 ppm. The FC would drop quickly from the large amount of algae in the pool -- you need to keep adding chlorine to MAINTAIN the FC level, but do NOT use Dichlor (i.e. this product) for this purpose.

I certainly hope you don't have a plaster of fiberglass pool because the amount of copper you've put into the pool may very well lead to serious staining and if you have anyone with blond hair the copper can turn their hair green. You'll have to be very careful not to have the pH rise much above 7.4 and that will be hard to do while shocking the pool with chlorine. You should have instead just hit the pool hard with chlorinating liquid or 6% unscented bleach. See this link for how a pool that is green with algae can be cleared with chlorine alone. There are literally tens of thousands of pool owners who maintain their pool with chlorine alone with no need for algaecides, phosphate removers, metal ions, clarifiers, flocculants, or even weekly shocking. I already gave the links in the post before yours of how to get rid of algae and shock the pool.

I'm also guessing that your CYA reading isn't correct, especially if you are using test strips. You should get yourself a proper test kit -- either the Taylor K-2006 or the TFTestkits TF-100.

[runderwo]

I went to wal mart and got 6% huge bottles of 1.11 gallon jugs off brand. I never put in an algaecide, i thought i was putting in algae killer, not a preventative, i learned that lesson last year. I heard that my CYA was probably too low, but i don't want it to get high and the chlorine not work at all like when i bleach it at night. Are there household items i can use for raising CYA? I will ONLY use bleach from here! Same with household items for lowering ph? I will get it checked again at the pool store tomorrow (free water testing but not open on sundays) and post results. Should i add like 3 bottles of bleach in the morning and then at night? And should i dilute it?

[chem geek]

If it's off-brand bleach, make sure it's "Ultra" and not "Regular" or else you won't be getting 6% concentration. Even better would be chlorinating liquid from your pool store or hardware or big box store where it is likely 12.5% or 10%, though you can compare pricing to see if it's a good value. Also, if your Calcium Hardness (CH) is low, you can use Cal-Hypo as a source of chlorine for shocking.

I agree with you that you should not raise your CYA at this point, but I also doubt the numbers. Unless you measured it with your own good test kit, they could be wrong. Pool stores do not do these tests properly much of the time.

After you clear your pool, if you need to increase CYA you can get pure CYA from your pool store. As for lowering pH, you use Muriatic Acid which you can get from most hardware and big box stores (often in the stone/concrete section).

Do not dilute the bleach. Just add it slowly over a return flow with the pump running and then brush the side and bottom of the pool where you add it to ensure thorough mixing. Yes, add it multiple times per day if necessary to keep the FC up high -- I'd say 15 ppm FC at least. Of course, you need a proper test kit to measure such high FC levels.

[green pools]

I keep reading algicide is just a preventative and chlorine kills the algae which on paper you can think whatever you want to but anyone trying to clear a dark green pool is a fool if they do not use it.
If you have decided you want to spend a ton of money clearing up a dark green pool then go ahead and dont drain your pool and refill it. When comparing both draining/refilling to clearing up the pool, time-effort-cost all come into effect.
Draining pool-rent pump/hoses $75, chlorine washing walls/floor-$50, cleaning filter once-$free, adding water and chemicals back-$80-150 total $300 to 400
just clearingup pool, clean filter, start adding chlorine start 10 gallons, scrubbing the pool walls/floor, run filter 24/7 until pressure rises or water clears and clean again. depending on how bad dark green is clean filter 4-5 times. Not using any algicide will make the process take even longer. I have seen pools take 24 to 48hrs to clear but when dark green sometimes 6-7 days and by the time you get your electricity bill its crazy! also think about keeping your dark green pool at shock level this could be that long and the chlorine will add up fast in cost. Even if it takes $300 its much longer with alot more work but its normally costs more!
Just my 2 cents

[chem geek]

I keep reading algicide is just a preventative and chlorine kills the algae which on paper you can think whatever you want to but anyone trying to clear a dark green pool is a fool if they do not use it.

Though it is true that you want to physically remove as much debris as you can from the pool such as leaves, twigs, etc., a pool with dark green algae can most certainly be killed with chlorine alone assuming the CYA level isn't too high (if it is, then a partial drain/refill to lower it is needed). See this post for an example of a dark green pool getting cleared by chlorine in 4 days. Of course, having a good filter helps move things along much faster.

Chlorine will absolutely, positively kill algae, but again you need an FC level that is high enough relative to the CYA level. For a reasonably fast kill, shock with an FC that is 40% of the CYA level and by shocking I mean MAINTAINING that high FC level so adding more chlorine as the FC gets used. It is not a one-time dose.

I suppose there are tens of thousands of "fools" at this forum, The Pool Forum, Trouble Free Pool and elsewhere who are able to maintain their pools using chlorine alone (after proper initial levels of other water chemistry parameters) and who are able to clear algae upon spring opening using chlorine alone as well (again, adding some other water balance chemicals as needed, but not algaecide).

[green pools]

OK look at the whole picture, a dark green pool is one that has been let go and not taken care of for months. May I ask you how many pools like this have you fixed yourself?
How many of these pools have the people on these other sites gone and fixed?
Its so easy to sit and spout off numbers and tell people things which I want to say are correct but without seeing their pool and equipment along with how long the pool has been let go conditioner and chlorine will fix it but not fast.
with people losing their homes and banks not taking care of the pools until fined pools sit green until people who live around it call in.
So a REAL dark green pool can take 6-7 days your way maybe even more with all the sludge in the pool. I would guess people just love cleaning their filters 4-5-6 times? Oh and if they have the good old sand filter the worst one it could take even longer to clear the pool.
Is electricity cheaper than water over a period of a week or more running your pump 24/7?
If the pool is dark green but only 2-3 days using an algicide is not a bad thing and will cut the cleanup time in half which FAST is what the person wants.
I have done this both ways and in the end if its a REAL dark green pool than dumping your water, chlorine washing the walls, cleaning your filter once and readding water and chemicals would be the most cost efficient way.

[green pools]

I never talked about maintaining your pool with algicicde I only bought it up with dark green pools. I think the most important thing to remember is people want their pools fixed fast so they can swim on a holiday weekend/birthday and of course during the summertime.
Every green pool cleanup will be different in the amount of time it takes to clean it up depending on how long its been green, how good is their equipment and keeping chemicals correct. So with all of this and needing it fast an algicide will help speed up the process and save money doing it.

[green pools]

have you ever seen the bottom of a drained dark green pool thats been sitting for months? please go ask all the guru's at the other sites the same thing and let me know the answer please.
please note I am not trying to argue just stating fact sometimes algicide is good to use....

[chem geek]

The example I showed in the earlier post was a pool opened on spring opening. The examples below from TFP are for more seriously fouled pools such as those neglected for months or even years as is now being more frequently seen with foreclosures. I am using links for the photos because most are too large to be posted on this forum. As I wrote, it is very important to physically remove as much debris as possible. Sometimes pool services use ProTeam® System Support to raise debris to the surface where it can be more easily skimmed/removed (this product also produces hydrogen peroxide which is an oxidizer). More seriously fouled pools take longer to clear, but algaecide does not oxidize algae so it does not get rid of it. It can only slow down or stop algae growth, but in a pool that has been neglected for months the algae amount is in stasis since all algae nutrients will have been taken up by the algae. So algae dies and new algae grows, but the total does not continue to climb in such pools. There is a limit of 6 links per post so I have multiple posts.

Before
After

Before
After

(continued on next post...)

[chem geek]

Before
Before
In-Progress (plaster has issues)

Before
In-Progress (still in cloudy stage; final photo not posted)

(continued on next post...)

[chem geek]

Example of debris

So when you say you use an alagecide, what specifically are you using? Some phosphate remover products, for example, have clarifiers in them to help clear the water from the cloudiness produced by lanthanum carbonate so the clarifier can sometimes help clear a pool faster if the water is cloudy from suspended particles and the filter is poor (say, a sand filter instead of DE).

So to be clear, with a seriously fouled pool one wants to first remove any physical debris (leaves, twigs, etc.) and if a lot of the algae is settled then one can also carefully vacuum-to-waste. Alternatively, one can use the ProTeam® System Support product to raise debris to the surface for removal (and to start oxidizing algae with the hydrogen peroxide in the product). In extreme situations, one can replace the water completely which can be less expensive in some cases.

After physical removal of debris or more easily removed settled algae, then one can use an oxidizer to begin clearing the pool and can use filtration/backwashing/cleaning of the filters. The least expensive and very effective oxidizer is chlorine. Again, algaecide is not an oxidizer. Chlorine will also kill algae as well as oxidize it. The dead algae will turn from green to gray and it is this gray/cloudy stage that is usually the longest phase to clear. Some people use clarifiers (e.g. GLB® Clear Blue®) or flocculants (e.g. OMNI Liquid Floc Plus) to speed up this stage. Though not necessary and not always effective and are extra cost, they do speed things up when they work.

[green pools]

I would guess you have not gone to a green swamp pool and fixed it yourself? I would suggest doing this so you can get first hand experience at it and understand everything that really goes on.
This is why I first wrote about a dark green pool and said the cheapestest way would be to drain pool, chlorinewash walls/floor, clean filter, refill and add chemicals. Can be done within 48 hrs so you save time and money and enjoy the pool.
When cleaning up a green swamp theres alot more time, effort, money envolved which is less pool time and unhappy kids.
Like I said before I have gone to green swamp pools before and have done it both ways chlorine only and chlorine and algicide and guess what using algicide is faster.
another thing, why do people want to wait until dead algea falls to the floor so they can vacuum it to waste using a sand filter when you can have a DE filter or cartridge filter that catches it when filtering?
I could not see all the pictures but which one of them where not extreme situations to replace the water completely? 20,000 gallons around here is $70-80 tops