Hey All,
Looking for some help in regards to an algae bloom that we just can’t seem to kick.
Some background:
We have an approx 28,000 gallon inground pool with sand filter. This is our 5th summer in this home with this same pool/filter setup. Usually once or twice per summer we have gotten algae issues but have always solved them by shocking the pool, sometimes to very high levels (30 ppm per chlorine) but always with a return to normalcy afterwards.
This year we hit an algae issue towards the end of June that still hasn’t been fully resolved 3+ weeks later. The initial issue, we believe, was that the CYA was too high (130 as measured by Leslie’s) so our shock wasn’t working. We went through a regimen of draining and refilling to get our CYA down (80ish) and then shocked again using a 73% hypochlorite powder shock. Over the course of 36 hours we used 12 lbs of this shock. The pool lightened slightly but never lost the green color. In our previous experiences shocking algae to a high chlorine level turned the pool an opaque bluish white within hours as long as we brushed well. Then our filter would gradually filter it out.
So, after unsuccessfully trying on our own to resolve the green pool we brought out a local pool company to attempt to fix. They got the pool to turn that bluish white opaque color that we had previously seen and we’ve been running filter 24/7 and backwashing and brushing daily. On Monday of this week the pool looked like it was on the right track. Still cloudy but we could actually see the drain in the deep end (9 feet). But by yesterday (Wednesday) we noticed a tinge of green and we cold no longer see the drain and after calling local pool company we shocked with 3 lbs of 73% hypochlorite. This morning, no change, perhaps slightly more green. One thing to note the free chlorine was approx 5ppm on Wednesday when the pool started to turn green, so it was not a simple low chlorine issue that started a new algae issue.
After a follow-up call with the local pool company (whom my impression is that they aren’t swindlers, but you never know) they said they thought that our sand filter is not up to snuff, and they think we should replace it with a 48 or 60 SQFT DE Filter. I am skeptical. One, we had the same setup for four years (and assume the previous owners of house had it for long time as well), our pump and plumbing seem to be in great shape. The only real change this season from last was a tree removal that allows the pool to get more sun. Our filter seemed to work fine for the last four years (and I even changed the sand two years ago), so to say the filter is the issue seems off to me. Additionally I will add that in previous years after killing the green and getting the algae to die and turn bluish white it did take 4-5 days to get a nice crystal clear water. So perhaps the filter doesn’t work as well as it should, but my question Is as follows: If the filter is not filtering out the dead algae at a quick rate will that be the CAUSE of a new algae outbreak? In other words does dead algae increase the chance of getting new live algae? I feel like it is a pool chemistry issue and not a filtration issue, but said pool company is trying to sell me on a new filter.
Looking for some help in regards to an algae bloom that we just can’t seem to kick.
Some background:
We have an approx 28,000 gallon inground pool with sand filter. This is our 5th summer in this home with this same pool/filter setup. Usually once or twice per summer we have gotten algae issues but have always solved them by shocking the pool, sometimes to very high levels (30 ppm per chlorine) but always with a return to normalcy afterwards.
This year we hit an algae issue towards the end of June that still hasn’t been fully resolved 3+ weeks later. The initial issue, we believe, was that the CYA was too high (130 as measured by Leslie’s) so our shock wasn’t working. We went through a regimen of draining and refilling to get our CYA down (80ish) and then shocked again using a 73% hypochlorite powder shock. Over the course of 36 hours we used 12 lbs of this shock. The pool lightened slightly but never lost the green color. In our previous experiences shocking algae to a high chlorine level turned the pool an opaque bluish white within hours as long as we brushed well. Then our filter would gradually filter it out.
So, after unsuccessfully trying on our own to resolve the green pool we brought out a local pool company to attempt to fix. They got the pool to turn that bluish white opaque color that we had previously seen and we’ve been running filter 24/7 and backwashing and brushing daily. On Monday of this week the pool looked like it was on the right track. Still cloudy but we could actually see the drain in the deep end (9 feet). But by yesterday (Wednesday) we noticed a tinge of green and we cold no longer see the drain and after calling local pool company we shocked with 3 lbs of 73% hypochlorite. This morning, no change, perhaps slightly more green. One thing to note the free chlorine was approx 5ppm on Wednesday when the pool started to turn green, so it was not a simple low chlorine issue that started a new algae issue.
After a follow-up call with the local pool company (whom my impression is that they aren’t swindlers, but you never know) they said they thought that our sand filter is not up to snuff, and they think we should replace it with a 48 or 60 SQFT DE Filter. I am skeptical. One, we had the same setup for four years (and assume the previous owners of house had it for long time as well), our pump and plumbing seem to be in great shape. The only real change this season from last was a tree removal that allows the pool to get more sun. Our filter seemed to work fine for the last four years (and I even changed the sand two years ago), so to say the filter is the issue seems off to me. Additionally I will add that in previous years after killing the green and getting the algae to die and turn bluish white it did take 4-5 days to get a nice crystal clear water. So perhaps the filter doesn’t work as well as it should, but my question Is as follows: If the filter is not filtering out the dead algae at a quick rate will that be the CAUSE of a new algae outbreak? In other words does dead algae increase the chance of getting new live algae? I feel like it is a pool chemistry issue and not a filtration issue, but said pool company is trying to sell me on a new filter.