Fourth SLAM this Summer due to algae. Am I doing this right?

[Swampwoman]

OP, while you're working out your plan of action, why not (post Slam) run your pump-filter 24 hrs a day and see what happens (eg. Chlorine production).

I'm not swg, but for other reasons, including the heater, we run ours 24 hrs a day. In our neck of the woods, the energy to run the pump constantly is the least of our expenses. Without a second swg, by running continuously you not only increase your chlorine production, but you keep the water moving....
Just a thought

 

[one_knight4u]

Upgrade your pool with a UV lamp. You will never have to SLAM again as long as the UV lamp is working.

Yes that may be true, but there are other factors involved here. Cost and maintenence, along with operating perameters. At $5,000+ for the initial baseline system and a $300+ light bulb every 2 years (14 months of continued service before UV-C output is diminished) is hard to justify. Another factor not included in that scenario is the addtional wear and tear on equipment running 24/7 to dose with UV light (water has to pass through the UV chamber for disinfection) along with additional electrical to run 24/7.

Given all of that, UV in my opinion is not even a consideration.

 

[Dagobah]

Yes that may be true, but there are other factors involved here. Cost and maintenence, along with operating perameters. At $5,000+ for the initial baseline system and a $300+ light bulb every 2 years (14 months of continued service before UV-C output is diminished) is hard to justify. Another factor not included in that scenario is the addtional wear and tear on equipment running 24/7 to dose with UV light (water has to pass through the UV chamber for disinfection) along with additional electrical to run 24/7.

Given all of that, UV in my opinion is not even a consideration.

Agreed, that's far too much $$$.

- - - Updated - - -

OP, while you're working out your plan of action, why not (post Slam) run your pump-filter 24 hrs a day and see what happens (eg. Chlorine production).

I'm not swg, but for other reasons, including the heater, we run ours 24 hrs a day. In our neck of the woods, the energy to run the pump constantly is the least of our expenses. Without a second swg, by running continuously you not only increase your chlorine production, but you keep the water moving....
Just a thought

I'll definitely be doing this post SLAM. More than anything, I'm wondering how the pool wasn't green in years past during the summer with my current setup with similar run times (and even hotter temps the last few summers). I didn't get a true DPD test kit until this year, so I'm not sure of my CYA or FC levels.

 

[chem geek]

Neither ozone nor UV will do anything for any algae that is stuck on surfaces and does not get circulated. We've seen plenty of pools with such systems get reported with algae. They help with killing free-floating algae, but not all algae types circulate.

 

[Tepelus]

For a pool of your size a uv lamp costs in europe less than 800€. One does not run the filtration systyem 24.7 for the sake of the UV system since it cannot be your primary sorced of desinfection. The UV lamp will not sanitise the surfaces of yor pool, but will sterilize 60% of the water in one passage and 90% ofthe water in two passages. Replacements tubes for the lamp cost 40€ a piece (80€ for the set) every 3 years assuming that you run the filtration system 12h every day for 9 months a year. There are some less known advantages for having a UV lamp: reduced chorine consuption and removal of the choramines from the water. A UV lamp will keep the water sterile even if there is nobody to take kare of the pool. Surfaces might get algae, but 99% of the water will be sterile and algae free. It is a great help.

 

[Dagobah]

Neither ozone nor UV will do anything for any algae that is stuck on surfaces and does not get circulated. We've seen plenty of pools with such systems get reported with algae. They help with killing free-floating algae, but not all algae types circulate.

So this got me thinking. I mentioned earlier I usually see a little sand in the pool every week presumably from the filter. I've also had some white calcium like deposits on the pool over the last 4 years, especially in the spa. These are hard, and don't come off with brushing. I had a pool guy take a look once, said he thought I just needed to brush harder. Either way, the algae that I see in the spa usually starts on these spots. Could this be contributing to my recurring problem? Here's a pic from day one of the SLAM showing both the sand and the deposits and algae in the spa.

 

[chem geek]

The pH tends to be higher in a spa due to aeration from jets (if you have/use those) and the hotter water is more prone to scaling of calcium carbonate. Scale can be rough and rough surfaces tend to harbor algae because circulation into the crevices is poor. Dilute acid can remove scale but you would need to be careful because your plaster is colored.

However, even if this area were where algae could grow, it would get killed in the bulk water or the swimming pool water if the FC level were consistently maintained. It could, however, produce a higher chlorine demand (if there were a lot of algae) and that would put more stain on the SWG cell trying to keep up since it's already on the edge.

 

[Tepelus]

If you have a opaque cover use it when you are not using the pool. Green algae growth rate is proportional with the amount of light available. When you use the cover you reduce the chlorine loss due to solar radiation as well.

 

[Dagobah]

I passed the overnight test a few days ago, but have been keeping the pool at SLAM level for a few days just as insurance. Today, I turned back on my SWG and noticed the power light on my Aquarite didn't light up. I cycled the system back to Manual and Auto again, and I got the no-flow light for a few seconds, but still no Active light. Wondering if this could be apart of my problem? The cell is less than a year old, so thinking maybe something is up with the Aquarite? What could cause this?

 

[Dagobah]

Well, turns out my aquarite had failed. The limiter on the board was burned out. I suspected something with the cell earlier in the year and had it tested (it passed) but didn't think the controller was the issue. Power still came on, didn't see any error codes, but was definitely not generating chlorine. The only sign was the generating light was NOT on. It's safe to say this was the cause of all my trouble this summer.

I followed instructions on the forum to solder in a new limited on the board, and it's been running great for about a week now. Chlorine levels have finally stabilized and things are back to normal (finally).

 

[Smykowski]

Glad you figured it out, and thanks for posting the followup. Hopefully someone will find this thread in the future and your story will help.