Getting rid of algae

[thegolls]

My pool is a 24" round vinyl pool. During the winter it became a breeding ground for algae. I got the water checked at the pool store and they told me that my TDS was 100, TC was 0, pH was 7.5, Adj Alk was 101 and tot hardness was 87. I added 3.5 lbs of stabilizer and have been adding bleach over the last 2 days. The water has gone from green to blue, but i still cant see more that 6" down. How long does it normally take to clear up? I have added about 6 gallons of bleach over the last 2 days. Not sure of it matters, but last summer I used Pristine Blue. I drained 3/4 of the water out a week ago and replaced it. I have left the filter on for 3 days strait so far.

Thanks

Jimmy

 

[woodyp]

You should probably backwash the filter/clean the cartridge. Could take a week depending on severity. Key is MAINTAINING shock level of FC until it passes the overnite drop test as described in pool school. It would have been easier to hold a lower shock level without adding the CYA until it cleared. Do you know what your CYA level is? That is key to knowing shock level. Chart----------you guessed it------------in pool school.

 

[thegolls]

I assumed that by adding the stabalizer i was helping the bleach stay in the pool. I though i read somewhere that with out the stabalizer the sun would get rid of my chlorine faster than i could add it. My CYA level was at 0.

 

[duraleigh]

I assumed that by adding the stabalizer i was helping the bleach stay in the pool.

That's correct. Two things consume bleach (chlorine). The organics present in your pool water and UV rays from the Sun.

CYA (stabilizer) reduces the loss of FC to the sun but doesn't completely eliminate it. An algae (organics) laden pool will consume chlorine very rapidly as well so when you are trying to clear a pool, it is important that you continually replace the chlorine so it stays at a high level and can continue to defeat algae.

The whole thing is a process rather than a one time dosage. Pool School has several articles describing in detail how to perform this process and what the practical meaning is of your test results. I would suggest you start with ABC's of Pool Water Chemistry.

 

[frustratedpoolmom]

If you haven't yet invested in a good test kit, like the TF100 or the Taylor K2006, then that's your next step.

 

[thegolls]

OK i finally ordered and recieved my test kit.

While waiting on it, I blindly added about 18 Gals of liquid bleach over about 2 weeks. Trying to keep it at shock level with a cheap walmart tester.

Here is the number I got with the tf100

FC : 6.5
CC : 0
TC : 6.5
pH : 7.5
T/A : 250
CH : 100
CYA : 25
Temp : 68

My water still looks cloudy. I can only see about 6 inches down clearly. I can see my fingertips till about 1 foot down but its really blurry. I have been running my filter 24/7 for 2 weeks now. What do I need to do to clear this water up? Do you think getting in it and stirring it up some would help the filter? I'm sure my kids would volunteer for that job.


Thanks

Jimmy

 

[Bama Rambler]

What type filter do you have?

You can do the OCLT (overnight chlorine loss test) and if you pass, your filter just needs time to clear it out. It can take a week or so after killing everything to completely clear the water.

 

[thegolls]

I have the standard 2 Hp pump/25 gal sand filter that came with the pool. I think the brand is columbia.

 

[Bama Rambler]

Is that a 2-speed pump?

The 25 gallon filter holds about 200 lbs of sand so it's about right. It takes a sand filter a while to completely clear a pool in the shape yours was.

Have you backwashed it lately?

 

[thegolls]

As a matter of fact I Just walked inside from backwashing it. The pressure had risen a bit but I was trying to hold out to backwash it until tonight. Unfortunatly I was adding a few inches of water and forgot about it until it was an inch away from the top of the skimmer. So i had to get rid of some of the water. The water that came out was milky looking. So i know the filter is working. But it just seems like it should have gotten better in 2 weeks now.\

As for the pump. It only has on and off switch so im assuming its only a 1 speed pump.

 

[dmanb2b]

A sand filter is more efficient at filtering, when dirty so as long as PSI does not rise more than 8PSI from you clean PSI, I would avoid backwashing. The other issues is that a 2hp pump is way overpowered for a 200lb sand filter, unless it is a two speed, then definately kick it down to lowspeed. The 2hp pump is likely pushing the dead alage right through the filter. Also, (I know this is a given) but make sure the multiport valve is set to filter vs recirculate. You may also want to try using a skimmer sock as it would help catch some of the dead algae.

Hope this helps somewhat

 

[thegolls]

So should i be looking to get a smaller pump or a bigger filter?

 

[Bama Rambler]

Dman hit on the reason I asked if it was a 2-speed pump. A single speed pump that large is possibly too much for a filter that size. I'd add a skimmer sock to the skimmer and see what that catches.

I'd look at both, but definitely a smaller pump. A 3/4 or 1 hp pump is enough and I'd still go with a 2-speed.

 

[thegolls]

I cant guarantee the size of my filter. I went off photos I googled. Here is a pic of the filter and our cloudy water.

 

[Bama Rambler]

That looks like a 25 gallon filter. Can't tell about the pump though.

I like the second suction plumbing. I'd probably figure out a way to add a float valve (i.e. ball) to the skimmer so it'd shut it off if the level got low and allow the bottom suction to keep working. (you may already have done that!)

 

[thegolls]

I do know for sure the pump is a 2 hp. It says so on it. The 2nd suction is so my skimmer will still work while the vacuum cleaner is going. It also helps so that I can leave the vacuum always going and if it gets clogged up by leaves (it has an inline skimmer basket) the skimmer will provide the water to the pump so it wont cavitate. I havent had any problems with it so far.

 

[thegolls]

So I did the overnight chlorine loss test .

Yesterday afternoon I got in the pool and stirred it up and brushed the walls and floor really good. Didn't feel slimy at all. I added a gallon of bleach after i got out. If i remember correctly the FC was at like 6.5 before i got in. At 2130 last night the FC was 11 CC was 1 for TC of 12. 0630 this morning the FC was 11 and CC .5 for TC of 11.5

Is the presence of CC a sign that I still have algae? Or was it just there from me getting in there and stirring it all up. Can i let my PC back down to normal now?

Thanks

Jimmy

 

[Bama Rambler]

Since you passed the OCLT with flying colors, I'd let the FC come back to normal for your CYA. Now it's just going to take a little time for the filter to do it's job.

If it's not getting markedly better in a few days, you can try some clarifier. We don't normally recommend it because the filters usually do a good job of clearing and sometimes the clarifier doesn't help either.

 

[zea3]

Hi Jimmy! I don't know if you get much rain where you live, but if you do you may want to consider moving your pump onto a raised platform to protect the bottom of the pump from rust. If you added a couple of unions to your plumbing it would be easy to accomplish. If you do decide to change out the pump or the filter that would be a great time to add the unions and an equipment pad to your set up.

 

[thegolls]

In Southern Georgia we get rain daily! You can see I left the pipe long and the pump and filter are like 5 feet away from the pool. The intention is to pour a slab next to the pool and cut the pipe and move them closer to the pool on the new slab. A bum back has prevented this for the last few weeks. Hopefully in the next week or 2 i will be able to get it poured.