Equipment repaired, algae won't respond

[JenT]

I've browsed all the other algae posts, but couldn't resist asking my own personal questions.

I have a 24', 52", above ground pool with vinyl liner. Hayward dream line filter with 1.5 hp power flo pump. We live in Missouri, and the pool receives sunlight all day (no shade at all).

When we opened our pool this spring, algae bloomed viciously as we replaced parts on our Hayward sand filter. Every time we thought we had it, a leak would spring elsewhere. The equipment is only seven years old - we have replaced all of the easy to reach gaskets, hoses, the control valve, the pressure gauge, the sand and the laterals within the past year. Things seem to be running smoothly now, though I fear there is something broken inside the pressure gauge area, as it seems to always be at 10 when running, even when there is a noticeable difference in return flow. When we replaced the control valve, we only replaced the actual valve (with the handle), so I guess the next step is to replace the other part of the valve assembly.

Except...the algae won't go away. I kept shocking and shocking, then realized the shock had stabilizer in it (sodium dichloro something or other), as well as the pucks I was using. So, after stumbling on this site several times, I stopped using those and began using calcium hypochlorite shock. All I had was a Walmart 6 way test kit and test strips, but from what I can gather the CFY was up to 120 - not too bad - and for the past 36 hours I have kept the FC level at or above 25 (using the test kit drops with dilution as described elsewhere on this site). Which is not quite shock level for the CFY level, according to the chart, but should be adequate to make a difference, I would have thought. With the vinyl liner I was afraid to go much higher than that.

The filter has been running 24/7 for about 10 days, except for a couple of overnight halts to see if anything would settle. I last added algaecide 4 days ago, ran for several hours, let it stand over night, clarifyer 2 days ago.

There is no noticeable gunk on the bottom to vaccuum for about 4 days. I've vaccummed once a day for four days, we last went swimming four days ago and made sure to rub the walls and floor (which wasn't slimy at all). The water is still green and murky - visibility about 12 inches - no visible change. I feel like I'm missing something. There is slight algae growth on the ladder - other than that it is just the green, cloudy water.

I have drained the water to the skimmer level (about 4 inches), hoping to bring the CFY to more like 100, and plan on shocking again this morning once I've refilled the water.

Even if the filter is not filtering well, it is creating good flow (I would think, judging from the power of the return and the rotation of the water in the pool), the FC is adequate, and I am stirring things around several times a day trying to brush the bottom.

Sorry for the long rambling post - there's been a lot of circumstances I wanted to relay. I'm tired of spending time and money on a pool that no one wants to swim in, that I'm not sure is safe to swim in. I am ordering a Taylor test kit, but that won't help me now. Is there anything I'm missing here?

 

[dattia]

I am sorry to say that what you are missing is the relation between the amount of CYA you think you have and the amount of chlorine it actually takes to bring the pool to shock level as it relates to your CYA. If you really have CYA around 120, you have been nowhere near shock level for your pool. I am not an expert at all, actually still a newbie... but I have taken a black, nasty swamp to clear and sparkly two years in a row with this method. It DOES work, but you must follow the instructions in Pool School. The info in there has taken the onus of guesswork off of our shoulders, but it must be followed accurately and completely to achieve the results that you want. You really need to lower your CYA level a LOT in order to have your chlorine be effective.

It took me more than a month to clean my swamp because I did slack off from time to time. Hang in there and you will have a clear pool.

 

[Bama Rambler]

Dattia is completely correct. If you don't bring it to shock level and hold it there you are spinning your wheels. And it's costing you more and making you more frustrated the whole time.

Your best plan of action is to get the CYA down to under 70. That will require draining and refilling half your pool. If you can't do that it'll take a long time and water doing small drain/refills. Once you get the CYA down and get the shocking process over with you'll be surprised how easy pool maintenance is.

 

[JenT]

Thanks for your responses!

I am draining the pool now, trying to get rid of at least a foot, which would be about 20-25% of the water, bringing CYA to below 100 hopefully. I had thought I'd get the CYA down fairly quickly by vaccuming to waste (that takes about 3" each time), but I plugged it into pool calculator and was shocked at how much I really needed to replace.

Since stopping the pump this morning, though, the pool has lightened it's green color, turning more of a chalky green, so I have some hope now that even below shock levels, the chlorine is working.

I will shock it once it is refilled to the level on the chart - I've been hesitant because the chlorine levels seemed so much higher than suggested on the shock boxes, and was afraid for the new vinyl liner.

Any advice for the 4 day weekend coming up, when we will be out of town?? I was thinking to keep it at shock levels right up to the time we leave Friday, and hopefully it won't be too bad when we get back Monday afternoon. I'm not sure I'm comfortable leaving the pump going all that time - and no neighbors to ask to deal with it.

 

[Bama Rambler]

That sounds like the best plan you have at the moment. If you had a timer on your pump you could have it run about an hour or so each day and that'd help. Even if you ran down to the local big box store and bought an outdoor timer and plugged it into it, it would be worth it to keep a little circulation going each day.

 

[hawkeye]

you need to leave the pump on 24/7 and while your gone until you have this cleared up pump,motor will be fine.... test and dose your pool with chlorine morning you are leaving and if you get cya to 50-70 very important! then the chlorine will be holding alot easier for you trust me the weekend your gone it might be low when you get back but as soon as you get it up to shock again keep it up there and test it...you really have to be around the whole time 24/7 and keep it at right shock level per your cya, or your spinning your wheels so to speak but keep at it! next weekend it will be clear i bet if you do....the best investment for your pool ever is a nice test kit..... like the taylor 2006 kit....mike