Need Expert Advice on path forward regarding low CSI

[jblizzle]

Funny how I can give basic advice to everyone, but then second guess myself on my own pool

Current test results:
FC 7
CC 0
pH 7.5
TA 100 (want to lower)
CH 130 (likely need to raise)
CYA 45
Salt 600 (want to raise)
Temp 78
CSI -0.37

Replaced a bunch of water a month ago to lower CH. Now it is "too low", but based on a previous post I created I have been just keeping the pH a little higher so the CSI stayed reasonable. All is well.

Finally intending to buy the SWG controller in the next few weeks. And now I am not sure what to do first.

I would like to get TA down to counter the SWG pH rise. But, thought I could use the SWG to help drive the pH up.
But, if I just added salt now to 3200, CSI would drop to -0.56
Then if I worked the TA down to 70 with a pH of 7.5 the CSI would be -0.75 ... oops
I suppose I could raise the CH (even though I know it will be going up due to evap) to 300ppm and then be back to CSI or -0.39

Anyone have thoughts on what to do first?

Seems like CH addition first would prevent my CSI getting too low either while lower TA or adding salt, but just seems "off" to me to intentionally raise it.

Can I effectively lower the TA if I only am driving the pH down to 7.5? Or maybe I should just let the TA drop slowly by maintaining the pH ... and possibly add CH in the future if it starts to get too low.
:blah:

 

[JasonLion]

You can't perfect everything at once

The TA will go down one way or another as long as you are keeping the PH in range. If you want to optimize CH level (ie keep them low for now) then you will need to settle with keeping TA higher than normal and deal with the resulting frequent PH adjustments.

I'd give the higher TA a try and see how often you need to adjust the PH before making a final decision.

 

[anonapersona]

Funny how I can give basic advice to everyone, but then second guess myself on my own pool

Oh, I know, it is still funny though!

My two cents here is that you are wanting to do something, anything. The CSI is fine now. You will need to fight all these dragons when you get the SWG but not now. You don't need salt now, wait until the SWG is in, or that same week perhaps.

When that is in, both the salt and the SWG, you will need to deal with the TA by way of keeping pH in line. You know you can adjust TA the fast way or the slow way. I suspect that it takes the same amount of acid. The fast way is a lot of measuring and fussing over aeration, the slow way is to just test pH and adjust as needed. The SWG will speed all that up somewhat so best to just let that be and let it proceed at the normal pace.

As for the CH and the effect on CSI, as the CH goes up due to evaporation, the required TA to balance the CSI will need to be lower. So, since you will be checking CSI each time you test, you will notice when you must push TA down a bit more by targeting a lower pH.

 

[jblizzle]

I guess my real thought was to get a head start on lowering the TA ... but clearly that seems to just snowball everything :lol:

Thanks for confirming that I had not overlooked something obvious. The wait and watch approach certainly seems the easiest for now

 

[linen]

The wait and watch approach certainly seems the easiest for now

Sounds lazy to me :tongue: I think you should take the OCD approach and jerk that TA level up...i vote for more BS (emmmm....baking soda that is) :blah:

 

[mas985]

I guess my real thought was to get a head start on lowering the TA ... but clearly that seems to just snowball everything :lol:

I am guessing but given your location, I suspect your situation is much like mine where the evaporation is high and your fill water is high in both TA and CH. If so, I wouldn't bother adding any CH or trying to lower TA because both will rise over time and probably pretty quickly.

The best/only solution I found is an acid dosing system of some sort. Some have chosen a peristaltic pump but this is what I use: homemade-acid-or-chlorine-injection-system-t4174.html

CH will keep rising and with the dosing system TA will stabilize to a specific value. For me it is around 120 ppm. I just keep PH at a level that gives me a slightly negative CSI (0 to -0.5).

Also you might want to consider a controller that can handle both the SWG and the PH. There are several on the market now.

 

[jblizzle]

Funny you mention that as I was just thinking about an acid setup. I already have a Hayward T-cell, so was intending to get the Pro Logic to run power up the cell AND control my solar. I was tossing around the idea of their Sense & Dispense system, but did not like the price and was not going to use the ORP side of it anyway.

So I was starting to wonder if there was a decent stand-alone acid system (with a sensor) or if I should look at what is described in that thread (I had just run across it again yesterday and said, I really should read this again).

Of course then I got to wondering if the Pro Logic would somehow interface with one of these non-Hayward systems.

I could just sell the T-cell I have, and not go the Hayward P4 route, if there was a different system that made more sense.

Pretty basic setup: I only have the pool, so was going to just automate the solar valve (and maybe a suction cleaner valve if I decide to go that way) and want the SWG and some ability for acid might be nice.

What systems do you know of for the SWG and pH?

 

[mas985]

The sense and dispense works with several of the Hayward products including the AquaRite and AquaPlus units: http://www.hayward-pool.com/pdf/literature/LITSD11.pdf

But the only other unit I would consider would be the Pool Pilot: http://www.autopilot.com/our-products/c ... rol-System

 

[jblizzle]

I was just reading the Sense and Dispense manuals ... looks like for pH control it just controls a relay on a 120V supply, so any acid pump setup could be attached to it and not just the Hayward AQL-CHEM-3 setup which is just the Stenner setup.

Wish it was possible to just buy the pH sensor and not the combo with the ORP sensor. What I have not yet seen an answer for is whether I can disable the ORP or for that matter not even install it and not have error messages. Just will require a little more research.

My tap water is actually not too bad the times I have tested it:
CH 100-150
TA 70

So, I need to just see how it behaves with the SWG and consider the acid system as a possible future addition.

 

[mas985]

Why do you want to disable the ORP system? That is used to turn the SWG on and off so you don't have to worry about the correct % setting.

From the website:

Sense and Dispense consists of two kits. The first kit senses pH and chlorine levels and dispenses a self-renewing supply of chlorine generated from salt. pH dispense can be achieved using the second kit, which includes a manifold that connects to a CO2 tank or an carbonic acid feeding tank. These are highly effective solutions to lower pH as it tends to drift up with salt-chlorinated pools.

 

[jblizzle]

Based on the reading I have seen here ... the ORP sensors do not play nicely with CYA above like 30ppm or something. There were a few threads that discuss this ... in fact I think JasonLion is one who has diable the ORP sensor due to the FC going all over the place.

I do now see in the manual that the ORP sensor output can be ignored and just use the typical % settings.