Going away, SWG and suspect algea outbreak

[jesper]

How long pucks last is based on water flow and temperature.

Can you get a floater for the pucks? Putting in the skimmer is not a good idea as they are very acidic.

Yes, I can get a floater - but won't that just move the problem to the PVC cover ? The cover floats on the surface of the water.

I have read about issues regarding putting pucks in a skimmer, the guy that built the pool told about stories where the pipes below the skimmer had been 'eaten away'. So clearly it is not a great idea - but for a couple of weeks it might be better than risking the cover ?

 

[jesper]

So.. it sounds like you have a few days before you leave.. if that is the case.. get some CYA for the size of your pool (again use the pool math app). You should be able to get it to into suspension in an hour or so. by putting it in a sock, letting it get mushy, and squeezing it out. Some people put the sock in their skimmer baskets. The water flow in the basket has the same basic effect as squeezing but slower and you don't have to monitor it... Then once in suspension it will take days to stabilize..

Under shoot the CYA .. that is target for 60. if you overshoot you will have to drain and refill to lower it.

Yes, based on Tenab's earlier feedback that was my plan to try to raise CYA before I leave. Great you think it is doable.

I think I'll go shopping on Monday morning for
- CYA to raise to 60
- Pucks & floater, not 100% I'll need them, but won't be too expensive to have as a backup.

When I get back tonight, I'll measure FC, CC, pH and assuming FC is >= 6 after running the SWG at 100% for since last night. I'll turn off the SWG and do an OCLT overnight, hopefully telling me if I have an algae problem to deal with, or "just" need to find a way to maintain FC for the 12 days I'm away.

I'll also try to find someone that can make FC measurements, adjust SWG production/pump run-time and add pucks if need be.

One question I still have, do I need to worry if FC goes too high while I'm away, or can I set the SWG production on the "high" side avoid it becoming too low ? This will be particularly relevant if I fail to find someone that can make FC measurements while we're away.

Thanks a lot for all the advice. I'll update the thread tomorrow once I have some data.

 

[mguzzy]

I don't think so.. I don't think it can go too high to damage any equipment..at least not in the short term. no one will be swimming in it anyway. If it got high for awhile it would just be like a SLAM kinda thing anyway. When you get back you'll have a better feel for how you pool manages itself with the SWG and going away for 2 weeks won't be a big deal. Until then finding someone that can do some basic monitoring will help.. and if you have internet where you are travelling, we are only a mouse button click away.

Have a good trip

 

[jesper]

Just got home FC 11.2 after approximately 28 hours of filtering and SWG running at 100%

There is something in the water and some white deposits on the floor. Turned off the SWG, will see what FC looks like tomorrow morning

 

[jesper]

FC is holding overnight, did the 10ml sample and got

FC 11.5
CC 0.5

And in daylight the water appears clear.

So looks like if I had some algae they are gone now.

I tried moving the white deposits at the bottom with the brush, it appears as some dust flakes that gets mixed up in the water when touched.

I remeasured CYA and got a very different value than a few weeks ago, one I cannot explain by the amount of dichlor added since then. I now see CYA 90 so I don’t want to add any CYA. Maybe I didn’t properly mix the water and R-0013 sample last time, and I got a false reading? I’ve only measured CYA these two times. Or is it possible that my fill water had a high CYA content? All I know is that It was sourced by the pool company from a well.

As for going away, I’ll restore the pump to it’s usual program and the SWG to 20% output and see how FC changes between now, Monday morning, and Tue evening before we leave. Based on that I hopefully can guess a reasonable setting for while we are away. I’ll also try and find someone to make a FC reading by the end of week so we can adjust.

In the end it looks to be just my paranoia, and it is all under control.

Thanks again for all the help and advice.

 

[frogabog]

Sounds like you got yourself a good plan there.

The fill water should have no CYA since it came from a well, although that doesn't mean someone didn't put some in (however unlikely). I'd call and ask the pool co. If it's 90 though, well there's no SWG CYA chart for 90 so I hope someone else chimes in. Maybe do the test when the sun is high with your back to the sun and see what you get then.

The filter should get those particles if you run it, maybe longer than normal or even 24/7 till they're gone.

 

[jesper]

 

[frogabog]

Eh, looks clear to me. There's always some particles, just easier to see them at night in the lights. The filter gets them.

 

[frogabog]

I see you! haha! By the light. Don't drop your phone in the water. :~}

 

[jesper]

Sounds like you got yourself a good plan there.

The fill water should have no CYA since it came from a well, although that doesn't mean someone didn't put some in (however unlikely). I'd call and ask the pool co. If it's 90 though, well there's no SWG CYA chart for 90 so I hope someone else chimes in. Maybe do the test when the sun is high with your back to the sun and see what you get then.

The filter should get those particles if you run it, maybe longer than normal or even 24/7 till they're gone.

I’ll check with the pool company if they added any CYA, either when commissioning the pool (long story, but they did so while I was not here, despite explicit instructions otherwise), or if they might have done so afterwards.

I’ll remeasure CYA in the afternoon, my only concern is that I only have enough reactants for 5-6 CYA measurements in total. But now with the SWG it should stop going up so I won’t need to retest often once I’m sure I get a good measurement.

I’ve had the issue of white deposits below the intake from the beginning, they settle there due to less circulation I suspect. The robot cleaner gets them.

 

[jesper]

I see you! haha! By the light. Don't drop your phone in the water. :~}

No trying hard not to drop it!

Yes now in the morning the water appears clear, only last night in front of the light did I see some particles. That was after running the filtration non stop for 28 hours. Maybe I need one of those supplements that attracts small particles and makes filtration easier. Anyway, this is a small problem I can deal with when I’m back again. Now I just need to make sure I maintain FC in range while I’m away.

 

[frogabog]

No supplements/potions! They aren't necessary and can be problematic. Chlorine and filtering works just fine. You can add a little DE to the top of your sand filter if you wish to help it catch some smaller particulates than the sand alone can catch. It will wash out with backwashing, of course.

Also, a dirty filter actually can work better at the small particles than a recently backwashed filter.

 

[jesper]

Thanks will stay clear of supplements. DE filters aren’t common here, never seen DE in a pool supply store, but will look around when I’m back.

Just wired up one of the relays on the SWG in parallel with the pump timer, this allows the SWG program to control the pump, and in turn the SWG production.
The main advantage is that I can now control it from my phone while away, and don’t have to fiddle with the timer in the machine room.

 

[jesper]

Spoke to the owner of the pool company, he said his team would have added "some" dichlor when they commissioned the pool - when asked how much he said 2-3 kg, but I got the impression he didn't really know.

Assuming it was 3kg, PoolMath says it should raise CYA by 44

I've added 2.5 kg of dichlor, for a further CYA raise of 36, so based on that a CYA of 80 is expected. I measured 90, so not completely off. The measurement isn't super accurate, and if they added 1/2 kg more, it would be pretty much at 90.

Think this means my earlier measurement of CYA 20 must have been wrong somehow, perhaps I didn't get the reactant and the water mixed properly.

I am sure glad I re-measured CYA this morning before going adding CYA, as I was planning on yesterday.

Based on the CYA/Chrlorine chart and extrapolating to CYA 90 I should keep a minimum FC of 5 and a target of 7, that seems doable. I can look at draining some water and re-filling to reduce CYA to 80, though I might just leave it like this.

 

[frogabog]

Backwashing/refilling might take care of it within the next couple months.

 

[mknauss]

The white particles look like calcium flakes. Coming from your SWCG. Do you monitor CSI? It is calculated for you in Poolmath.

 

[jesper]

The white particles look like calcium flakes. Coming from your SWCG. Do you monitor CSI? It is calculated for you in Poolmath.

PoolMath reports CSI -0.12 which is within the -0.6 to 0.6 recommended.

As mentioned I've had some white dust like deposits under the inlets from the beginning, even before the SWG was installed. Though it is substantially more this time, but I had put it down to a much longer pump run time as it was running 28 hours straight.

Just re-measured FC, it is now 9.5 having dropped from 11.5 since this morning, with only 1/2 hour run time of the SWG at 20% since then.

FC 9.5
pH 7.4
TA 110
CH 425
CYA 90
SALT 4000
TEMP 31 degrees celsius

 

[mknauss]

I suspect your pH rises pretty quickly with that high TA. Your CSI is positive at any higher of a pH.

 

[jesper]

The SWG I got installed has a pH probe and automatic acid dosage system, this should keep the pH pretty constant.

Before, when I was adding dry acid manually, I noticed pH rising and I had to keep on top of it. The last couple of weeks I don't think it has been above 7.6 before I brought it down to 7.2.

The first weeks of the pool was really hard to control the pH, i part I guess because it was a new plaster pool, but also TA was very high. When I first got the K-2006 test kit a couple of weeks after getting the pool, I measured TA at 240 and I got it lowered by aerating. I probably need to repeat that again to bring it further down.

Though, playing with the numbers in PoolMath, if I get TA to 80 and keep everything else the same, I have a CSI of -0.32 and it warns that it may cause corrosion and pitting of the plaster. Also the water is quite warm now 31C or 88F, going into autumn it will cool down, further reducing CSI. If I use TA 80 and TEMP 25C/77F then CSI is -0.41.

If CSI get too low, I risk being in trouble, right ?

 

[jesper]

The white deposits were complete powder that dispersed as soon as you moved the water close to them. Using goggles you could see white flakes in suspension.

I brushed the walls and lots more white flakes came off.

Could this be old calcium scaling on the walls/pipes from when pH wasn’t under control ? Maybe it is slowly getting dislodged now that I got the balance under control?