Converting to chlorine from PermaSalt

[Mdragger88]

I’m above the recommended FC levels for my CYA level currently and plan to keep it that way. Bought plenty of bleach and a second fas dpd test kit. I’m just weary of draining an older liner down that far because I don’t want to possibly damage it. So I’ll have to be content will smaller water changes.
As long as I over shoot the recommended fc levels I can manage smaller water swaps and still stay in SLAM range.

The no drain exchange is pretty simple- drain from one end while adding water at the same rate to the other end - the water level in the pool never changes so its the safest way to exchange water.
Depending upon your fill & pool temps you choose top or bottom of the pool to place fill hose or pump to reduce mixing.

 

[Bperry]

I’m above the recommended FC levels for my CYA level currently and plan to keep it that way. Bought plenty of bleach and a second fas dpd test kit. I’m just weary of draining an older liner down that far because I don’t want to possibly damage it. So I’ll have to be content will smaller water changes.
As long as I over shoot the recommended fc levels I can manage smaller water swaps and still stay in SLAM range.

You should not overshoot the SLAM level FC as that just wastes expensive chlorine to the sun. The goal is NOT to stay above SLAM level, its to keep bring it back UP to SLAM level as needed.

 

[cm35]

The no drain exchange is pretty simple- drain from one end while adding water at the same rate to the other end - the water level in the pool never changes so its the safest way to exchange water.
Depending upon your fill & pool temps you choose top or bottom of the pool to place fill hose or pump to reduce mixing.

Ah. I see.
I was draining to lower limit, then was just filling pool structure all the way to top, let it dilute water in pool, then bypass to waste down to absolute min level was my original thought.

But I see your idea working too. I need a small pump I can hook to water hose for lowering level while filling on opposite side.

Thanks for the idea!!

 

[Mdragger88]

Ah. I see.
I was draining to lower limit, then was just filling pool structure all the way to top, let it dilute water in pool, then bypass to waste down to absolute min level was my original thought.

But I see your idea working too. I need a small pump I can hook to water hose for lowering level while filling on opposite side.

Thanks for the idea!!

Pump from the deep end or near the surface?​

To determine whether you pump from the deep end of the pool or from near the surface of the pool, depends on your fill and pool water characteristic.

Adding water to the deep end while pumping from a top step or near the surface is recommended if your fill water is much colder (>20F) then the pool water.

Put the pump in the deep end and fill from the shallow end if your fill water is nearly the same temperature as the pool water, you have a saltwater pool, or have very high CH. Put the fill hose in the skimmer, if you have one, in the shallow end. If no skimmer, then use a bucket to put the water hose in and have the top of the bucket above the pool water surface. Be sure to secure the hose to the bucket.

Replacing water in-place process depends on several factors:[4]

• Pool Water TDS (PWTDS)
• Pool Water Temperature (PWT)
• Fill Water TDS (FWTDS)
• Fill Water Temperature (FWT)

DeltaT = (PWT - PWTDS / 165) - (FWT - FWTDS / 165)

If DeltaT is positive, then you want to fill at the lowest point and extract at the surface and at the greatest distance from the lowest point.

If DeltaT is negative, then you want to extract at the lowest point and fill at the surface and at the greatest distance from the lowest point. <-Preferred as it is easier to do with a drain pump and you can fill inside one of the skimmers.

If |DeltaT| < 5, then there will be a lot of mixing.

Salt is the largest component of TDS. No matter what chlorination method you use, salt is added to the pool water and can be significant after many years. Every 1000 ppm of salt is worth about 6F in temperature difference.

Balance the water flow out and in​

Be sure to balance the water out and water in so the pool level stays the same.

When you have the pump you will use, take the effluent hose and fill a 5 gallon bucket while timing it. Calculate your gallons per minute (gpm) from that. Then you can estimate how long to run the process.

It is suggested to exchange 5-10% more water than needed to reduce your CYA/CH/etc to account for errors.

Be sure your pool pump is disabled during this process.

Once started do not stop until complete​

 

[cm35]

Great information. Thanks.

 

[cm35]

My fill water is really cold. That means I’ll fill to the bottom and draw off of the top on opposite fill side. I have a pvc thing I made to draw off the bottom one time. Like a snorkel just pointing down instead of up. I’ll modify it to be used as a filler. I already have the fitting for water hose hookup. It hangs over the railing and stops just off of the bottom.

 

[cm35]

Ok.
The SLAM is not going like I thought.
I never had green water like some of the pics we’ve seen on here THANK GOODNESS!! But the SLAM has taken over 15 gallons chlorine. CC levels have been constant at either under .4 or under .5 depending on sample size since Wednesday 7-3-24. I was even dosing heavy before I understood the SLAM. Started doing the 10ml size to conserve drops. Bought second fas-dpd test kit. Anyways the free chlorine dropped almost 10 ppm overnight from 28 to 8.5 this morning at 5:30am.
Geez I can’t keep doing this. Could this be loosing from extreme 100 degree heat. Like I mentioned CC is barely registering. No objects in pool.

I suppose I’m having difficulty understanding algae in the water but virtually zero CC

This pool has been dosed hot for over a week even before SLAM.

Filter is super clean with new sand. No debris in water. No steps or ladders. No swimming. No animals in water. No rain.

Is the SLAM over and I just don’t realize it.

 

[cm35]

My apologies. FC dropped just over 10 points. Not 20.

 

[cm35]

The chlorine was just vanishing with never any CC above.5 at any time. Like yesterday it was just guzzling chlorine jugs. CYA around 60 on one test but near 80 on another. I’m not certain about viewing the black dot at the bottom of tube. It gets almost invisible every time I do the test but never actually disappears.

 

[Bperry]

The chlorine was just vanishing with never any CC above.5 at any time. Like yesterday it was just guzzling chlorine jugs. CYA around 60 on one test but near 80 on another. I’m not certain about viewing the black dot at the bottom of tube. It gets almost invisible every time I do the test but never actually disappears.

Almost invisible is fine, you kinda have to learn to just glance for the dont and dont stare at it.

 

[Homebrewale]

I didn't see anyone mention it but the results looks like you are using the 25 ml sample for testing FC. You don't need the 0.2 ppm accuracy. To save on testing supplies, you can use the 10 ml sample size and each drop is 0.5 ppm.

 

[PoolStored]

the black dot at the bottom of tube. It gets almost invisible every time I do the test but never actually disappears.

That means your CYA is very low.

Try this. Get your mix. Pour to the first line. Hold tube at your waste, back to the sun so the tube is in your shadow. Glance down into the tube. If the dot is obscured, take the number next to that line and add 10, that is your CYA. If you can still see the dot at that line, fill to the next line. If obscured, take the number next to that line and add 10 for your CYA. Continue filling to each line until the dot is obscured. Add 10.

If you get to the top of the tube and you can still see the dot at a glance, your CYA is 20 or less.

 

[cm35]

Ok. I’ll try that. I was thinking it was around 50.
The dot would become harder and a little more harder and a little more harder to see and that change would stop around 50 -60. Then if I kept filling tube the rest of the way I could always still barely barely still see it. I thought it was to “disappear”.

I’ll try it the way you mentioned.

 

[cm35]

I didn't see anyone mention it but the results looks like you are using the 25 ml sample for testing FC. You don't need the 0.2 ppm accuracy. To save on testing supplies, you can use the 10 ml sample size and each drop is 0.5 ppm.

I started using the 10ml because I was really going through the drops.

But the FC was just vanishing with never any real CC to mention.

 

[cm35]

That means your CYA is very low.

Try this. Get your mix. Pour to the first line. Hold tube at your waste, back to the sun so the tube is in your shadow. Glance down into the tube. If the dot is obscured, take the number next to that line and add 10, that is your CYA. If you can still see the dot at that line, fill to the next line. If obscured, take the number next to that line and add 10 for your CYA. Continue filling to each line until the dot is obscured. Add 10.

If you get to the top of the tube and you can still see the dot at a glance, your CYA is 20 or less.

So when you say “obscured” are you meaning something like really white cloudy that tries to block out the dot like a fog?

 

[cm35]

So my next job is to straighten out the cya.
Then maybe do this SLAM all over again?

 

[PoolStored]

Good pics here of what it looks like...

CYA Testing - Further Reading

www.troublefreepool.com

 

[cm35]

Good pics here of what it looks like...

CYA Testing - Further Reading

www.troublefreepool.com

Nice!!!!
Thanks. I still think I’m in between 50-70.
I’ll post back this afternoon when I get home.

Thanks everyone.

I guess it’s hard to believe algae can survive with all the gallons of bleach I’ve used. And my wallet feels the struggle.

Why doesn’t someone make a puck without stabilizer.

 

[Bperry]

Why doesn’t someone make a puck without stabilizer.

They do, its called a SWCG and its powered by electricity.

 

[Mdragger88]

They do make calhypo pucks but you must use a new dedicated floater/dispenser and they add calcium of which too much is a bad thing (scaling)
I suspect your intense overnight loss is due to everything left over from your stair fiasco & the huge losses will subside soon.
Be sure to do all the things

But the SLAM has taken over 15 gallons chlorine.

That amount is akin to adding 11ppm fc 10x’s or 5.5ppm 20x’s in your pool volume - not unusual for a slam if dosing 3-4x’s a day as recommended considering you began nearly 7 days ago.

The steps held you back some days - keep going! You’ll get there!