New SWG and green pool

[ConnieStewart]

We have just purchased a new SWG that we are going to install this weekend. My question is about the condition of the water. It is green/algae (weather was unusually warm this spring). Should I shock the pool and try to get it cleaned up before I hook this thing up or will the SWG take care of this algae?

We have a 27" AG pool.

Also, do I understand that algae will be a thing of the past with a SWG?

Thanks for any advice!

Connie

[Watermom]

Shock the pool and take care of the algae before installing the SWG. As far as will the SWG prevent any further algae outbreaks, not necessarily. You will still have to make sure that you run it sufficiently to allow maintain adequate chlorine levels. Someone with further SWG experience may have more to offer. Hope this helps a little.

Watermom

[waterbear]

if the pool is green shock it first with bleach. Balance your water and make sure that your CYA levels are ok...most manufacturers of SWG seem to recommend between 60-80 ppm. Add your salt and brush it well to help it dissolve and then turn it on. You will then have to fiddle with pump run times and cell output to maintain the proper chlorine level and monitor your ph becuase salt systems will cause it to creep up. Bring it down with muriatic acid. (my 6600 gal fiberglass pool needs about 12-24 oz. every 4 to 6 weeks. Your milage may vary). During the summer I have my pump running for about 8 hours a day and have my cell output adjusted to maintain a 3 ppm chlorine level--right now at 10% but expect it will have to go up a bit as the weather gets warmer. I have never needed to shock it since it has been in operation last Nov.(as I live in FL I don't close the pool). When the weather was cold my pump runtime was 6 hours a day and the cell output was at 6% and I held 3ppm FC without a problem.

Once you get the hang of it it's really easy. Just test your water and keep on top of it. If the FC is low increase your output or pump run time. If it's high bring one or the other down a bit (or even both if needed). In the very unlikely event that you test CC shock with bleach as you would with any chlorine pool. You can superchlorinate with the cell (they will continuously generate chlorine for up to 24 hours) but it will shorten cell life. My builder did this the last time I had a green frog pond while it was being built (happened 3 times, once after the swg was finally operational and the salt was in the pool because he did not have the flow switch plumbed right and it didn't work). It took pea green water and made it crystal clear overnight! If I had known that it shortens cell life I probably would have just had him dump bleach in the pool!


Needless to say, once it was operational I have never measured CC, never had it turn green, and the bag of salt in my garage lasts a long time to keep my salt levels at 3200-3400ppm.

[mwsmith2]

I agree 100%. Hit the pool hard to 15 ppm. That will nuke the algae. Once the Cl drops down to a normal range (<= 5 PPM) let your SWC take over. That will clear out any remaining CC you might have. Balance the water and enjoy the pool!

Michael

[mwsmith2]

make sure that your CYA levels are ok...most manufacturers of SWG seem to recommend between 60-80 ppm.

Woah! That's generally accepted around here as being Too High. 40 ppm is plenty. High CYA will limit the effectiveness of your Cl.

Michael

[waterbear]

There was a discussion about this before the board crashed and I belive it was Ben (could be wrong) who said that in this case it might be better to follow the manufacturer's suggestion since dosing the pool with chlorine from a salt water generator was different than dosing it with bleach in that there is a small quantitly of water that is superchlorinated and then mixed into the pool whenever the pump and cell are operational as opposed to the dose being mixed into the pool and diluted right away and perhaps for this reason the higher CYA level are recommended. At any rate I run betwen 60-80 ppm CYA, keep the pool at 3 ppm FC and the spa at about 5ppm and have never had any CC or any algae growth!

It's times like this that you really wish the board did not crash. So much good info was lost!

[tonyl]

Waterbear is right. I keep mine at 70-80 ppm cya and 2.0~ chlorine for going on my 5th year without a hint of algae and my water hits 90 in Aug. Poolsean said he has many pools in S.Fla maintaining those same levels without problems.

[mwsmith2]

There was also mention of how high CYA levels lead to plaster erosion too. That's why I shy away from it. I do remember Ben discussing talking about running high CYA levels, but it seems to me that was more for folks on bleach who wanted to only mess with their pool once a week?

Michael

[ConnieStewart]

Thanks for everyone's help! I got the algae under control, got my SWG hooked up and I must say I LOVE LOVE LOVE it!!! So glad I made the switch! The water is so clear, so soft, and is more sparklier than ever (not to mention my DH is building me a deck all the way around it)! It's going to be a good swimming season, I can tell!!!

Thanks again!!!

Connie

[c130jake]

There was also mention of how high CYA levels lead to plaster erosion too. That's why I shy away from it. I do remember Ben discussing talking about running high CYA levels, but it seems to me that was more for folks on bleach who wanted to only mess with their pool once a week?

Michael

My brother the Masters in electro-chemistry says the higher CYA levels are required to allow for more free chlorine to be produced based on the salt content. It's that old cathode-anode thing I guess. I dropped out of P-chem 20 years ago cause it had too much calculus or I could explain it better...