HIGH CH! Understanding CSI

[Modawg2k]

Hola. I only started paying attention to my water a few weeks ago. 3 y.o. pool

Current Readings:
FC 4.5
pH 7.5
TA 90
CYA 50 (currently in the middle of raising it to 70-80)
Ch 800 (Tap water 225), scaling present

I've played around with the numbers in the pool calculator to see how it affects CSI. I understand that it uses "requires pH, TA, CH, CYA, Temp, uses Borate, Salt"

With my current numbers, my CSI is 0.2.
I'm going to set my target numbers at end of the ranges recommended:
pH: 7.2
TA: 60
CYA: 80
Borates (have not considered using this yet).

Does that sound like a good game plan? Am I missing anything?

 

[jblizzle]

Sounds like a plan if you are not ready to replace water. Lowering TA is easier said than done ... see the process in Pool School.

 

[Modawg2k]

The more I think about it, I should really drain it. Mostly because I think I need to acid wash my pool because of a staining issue during pool construction. Ill prepared rocks from my water feature stained my interior immediately upon pool startup. I still need to research acid washing before hiring someone to come do that. I may start a thread asking if my pool is indeed in need of an acid wash. Thanks for your time!

 

[Modawg2k]

If I decide drain, can you guys recommend some good threads that talk about how to drain? I haven't been able to find any.

I have a sand filter and I'm guessing backwashing isn't what I'm suppose to do for a pool drain.

Also, how do I know if there is a certain water level that I shouldn't drop below?

 

[jblizzle]

Well, you need to have some idea of the groundwater level around your pool. If it is below the pool, then you could likely drain the whole thing without a problem. If the groundwater is high, then if you drain too much, the pool could float itself out of the ground and basically you will have to build a new pool ... so it needs to be a serious consideration.

Usually the drain is best done with a submersible pump, either buy a cheap one or rent one.

What else do you want to know?

 

[Modawg2k]

Thanks. Where do I find out about the water level? I did a quick google search but didn't see anything.I'm pretty sure my ground doesn't have water anywhere close. There is about a 10 foot drop just past my backyard fence into an open desert preserve area.

 

[jblizzle]

Where are you located? Add it to your profile. It sounds like you likely do not have groundwater to worry about if you are on high ground.

 

[Modawg2k]

I'm located in Phoenix.

 

[jblizzle]

yeah ... I don't think you have anything to worry about ... I think our ground water is measured in the 100s of feet.

BUT, the current heat can be harsh on the plaster/pebble ... so would be best to do it at night.

Alternatively, you could look into the Reverse Osmosis treatment that is available up there ... although I think that is in the $300-400 price range.

 

[Modawg2k]

I will have to look into the pumps. I have a pump but it takes about an hour or more to drain my 350 gallon hot tub. I'm guessing that is not the right kind if its that slow? Or is that the speed I'm looking at with draining?

 

[Modawg2k]

Never mind, found pumps that do 50+ gallons per minute..... Definitely not like the one I have!

 

[Modawg2k]

Is the recommendation to drain only a portion of the pool and then fill and retest?

 

[jblizzle]

Depends what you are trying to accomplish. Your CYA is fine, so you have to decide how low you want to try to get the CH.

 

[Modawg2k]

Well, I guess I would want to get CH down to a level that is consistent with the levels that pool school states: 250 - 350.

 

[jblizzle]

Well, at best you can get it down to 225ppm with a complete replacement.

A 50% change should get it down to about 500ppm.

 

[Richard320]

Well, I guess I would want to get CH down to a level that is consistent with the levels that pool school states: 250 - 350.

Give it up. It ain't happening where you live. Your tap water is probably close to 200, if not higher, so within a couple weeks you'll be well above again, even if you drained 100%.

There is a reverse osmosis company in the Phoenix area, you could try them. I think they're called Calsaway. They can take it down to almost nothing. Of course, they'll also remove all the CYA and alkalinity, too.

 

[Modawg2k]

Thanks for the info. I just got a quote from him for $545. I don't see my budget being able to handle that though. I will probably have to look into the other alternatives