Mustard Algae SLAM in process...but, I have a couple questions

[Dustin1047]

Hi:

I have a mustard algae problem. Started the SLAM today. I already put 5 gallons of 8% bleach in and am about to add 3 more, based on the numbers below. I'm also going to turn off our solar heater, since I read here that algae doesn't grow as well in colder water (makes sense). My wife wants to know about swimming in it while I'm SLAMing. I just read where Butterfly posted that the FC should be under 10 before swimming, so I'm guessing that's a no swim whilst SLAM is in progress. Can someone confirm? Also, what about aeration while slamming? Should I leave the waterfall off or on? I searched the board and could not find the answer. Sorry if I missed it somewhere.

Current #'s below. I'll post more in a couple hours or if I have another question. THANK YOU for your help!! This is the greatest board I'm on. Most helpful!!

-Dustin

FC CC TC pH TA CH CYA
19.5 1.5 21 6.9 40 1560 62

 

[bridgman]

General rule is that swimming up to Shock/SLAM level is OK, but I don't think that applies to the higher Mustard Shock level.

It's a function of FC relative to CYA level, so for CYA of 62 PoolMath says the shock level is 24, so you should be good swimming up to FC of 24. Maybe leave a bit of margin in case your CYA reading is off.

I think the general rule is "turn everything on" when doing a SLAM (solar heater, waterfall etc..) to make sure that all the surfaces that could be hiding algae get a chance to "interact" with the chlorine. My guess is that outweighs the benefits of cooler water, but I'm not 100% sure. The idea of a SLAM is to keep the FC level high enough to kill everything at typical pool temps, so I would lean towards running water through the heater at least for a while.

 

[Dustin1047]

Hey Bridgman,

Thanks so much!!! I am shooting for the Mustard SLAM level of 35 FC that the pool calc shows me. So, no swimming till SLAM is over and FC is down to at least 24. Cool. Thank you. I will turn everything on, to get the chlorine into the nooks and crannies. I appreciate your kind assistance.

 

[Butterfly]

FC CC TC pH TA CH CYA
19.5 1.5 21 6.9 40 1560 62

pH is 6.9? pH reads a false 'high' when FC levels are above 10. So, your pH is actually lower.


I suggest you stop the SLAM, let the FC drop below 10, adjust pH to 7.4ish and the TA to about 70, then resume SLAM.

 

[Dustin1047]

Hey Butterfly, the pH was at 6.9 before I started the SLAM, so I put 20 ounces of Borax powder in before I began the SLAM to get it into range. I have not tested pH since I started the SLAM because of false readings. Do you think it's ok to continue?