First tests with proper test kit; and is it time to replace some water?

[dailygenesis]

Great. Suggest you update your signature to state using LC as that helps if you have questions in future on pool chemicals or testing.

Done!

 

[dailygenesis]

Well, if all goes as planned, I'm going to attempt my first no-drain water exchange tomorrow. I've got everything set. The main issues I'm dealing with in preparation are: 1) my pump and hose combination is only pulling water out at a rate of about 4.5 gpm, so it's gonna take a good long while (approximately 21 hours) to exchange all the water I want to exchange, and 2) the temperature differential between pool water and fill water is enough (I've been heating my pool lately so we can swim), but with ambient temps not quite full summer heat yet, I'm concerned that over the course of the 21 hours, the temps will drift down too close and mixing will occur. I'm gonna heat my pool up a little higher than normal overnight and hit it first thing in the AM as the sun comes out so hopefully that will be enough.

On the pump/hose issue, I went and got a 1" interior diameter PVC hose (my pump has an attachment for this) and this ramped up discharge to about 17gpm, but that's too fast for my fill side (and probably also for my sewer cleanout) and I couldn't figure out how to slow it down enough. I'm sure with enough time, or with a different pump, I could figure out something better but I ran out of time and so I think I'll just stick it out with the slow going 4.5 gpm.

I'll report back on how things go.

 

[PoolStored]

Well, if all goes as planned, I'm going to attempt my first no-drain water exchange tomorrow. I've got everything set. The main issues I'm dealing with in preparation are: 1) my pump and hose combination is only pulling water out at a rate of about 4.5 gpm, so it's gonna take a good long while (approximately 21 hours) to exchange all the water I want to exchange, and 2) the temperature differential between pool water and fill water is enough (I've been heating my pool lately so we can swim), but with ambient temps not quite full summer heat yet, I'm concerned that over the course of the 21 hours, the temps will drift down too close and mixing will occur. I'm gonna heat my pool up a little higher than normal overnight and hit it first thing in the AM as the sun comes out so hopefully that will be enough.

Get a 5 gallon pail. Fill with pump and time it. Get your fill hose, and do the same. Turn your fill hose down to match the pump. I was able to fairly match and the water level took about 4 hours to vary 1/4-1/2" so I didn't have to babysit and could sleep overnight.

 

[dailygenesis]

Get a 5 gallon pail. Fill with pump and time it. Get your fill hose, and do the same. Turn your fill hose down to match the pump. I was able to fairly match and the water level took about 4 hours to vary 1/4-1/2" so I didn't have to babysit and could sleep overnight.

Yes, I have done this. I have the inflow and outflow matched pretty well. I was just hoping to be able to get both up a little higher so it wouldn't take as long. But this should work, it's just going to take about 21 hours.

 

[PoolStored]

Yes, I have done this. I have the inflow and outflow matched pretty well. I was just hoping to be able to get both up a little higher so it wouldn't take as long. But this should work, it's just going to take about 21 hours.

Yeah, I think mine took like 36 hours. Kinda slow, but it works.

 

[dailygenesis]

Well, my first no drain water exchange is complete. Based on what I can see on my first post-exchange tests, I think it worked just about as expected.

According to my calculations, I replaced about 5,800 gallons of water, which is about 25% of my pool volume plus a ~10% buffer. It took 21.5 hours at 4.5gpm.

Here are the results:

• CH: 550 -> 450. Exactly what I expected. Fill water is 150ppm so a 25% replacement should reduce by exactly 100ppm.
• CYA: 60 -> 40. Pretty much what I expected. A 25% reduction would be 45ppm but since the test only goes in increments of 10, I think this is about right.

The only unexpected result I had was TA, which dropped from 80 to 50. Fill water has a TA of 40 so I would have expected to come out around 70ppm, but I'm guessing there are some more factors behind TA. My plan is to give it a little bit to balance out and then possibly raise it a bit if needed.

I wish I could have gotten CH down a little further but I think for my first attempt this was good. We'll see how quickly it raises back up and go from there.

The only thing I will probably do differently next time is try to schedule it in either to hotter part of the summer or a colder part of the fall/winter. Since the temperature differential between pool water / fill water needs to be as high as possible, picking a time when the pool water is at its extremes seems like a better idea. In my case, I had to heat the pool up a good bit to make sure the temp was high enough when I started. But, as @Dirk has pointed out, I need to avoid Dec-Feb so my sewer bill doesn't go up year round as a result of using too much water in the winter months.

Thanks to all for all of the advice on this thread.

 

[PoolStored]

The only unexpected result I had was TA, which dropped from 80 to 50. Fill water has a TA of 40 so I would have expected to come out around 70ppm, but I'm guessing there are some more factors behind TA. My plan is to give it a little bit to balance out and then possibly raise it a bit if needed.

Let your pump mix it up good for 24hrs and retest...

 

[dailygenesis]

Let your pump mix it up good for 24hrs and retest...

Good call. TA was back up around 70 after a day or so.