New to Pools Chemistry Question

[eGGnog]

Howdy all. I have been lurking here for a while in preparation for buying a house with a pool and it has finally happened. I received my taylor test kit the other day and started my adventure with pool chemistry. I ran into a couple roadblocks that I was hoping to get some clarification on if I could. The pool is a fiberglass diving pool of approximately 18k gallons. The previous owner used that fast dissolving chlorine in a tub that you just throw into the pool. The following are my test results:

FC - 10.4
CC - 0 ? Im not 100% on this, but according to the sticky thread here it appears that I did things right. I added the reagent and the water stayed clear, suggesting 0 CC
Ph - 7.4
TA - 110
CH - ?? This one I am very confused on. I ran the test using the smaller sample size and after 14 drops (350) the water turned a light sky blue. I wasn't sure if that was the right color so I kept adding. At 28 drops (700) there was no visible change to water color and I stopped. Is the blue supposed to be vibrant, or just a light sky blue color?
CYA - Registered off the scale. The dot disappeared with only approx. 1/4" of water in it, suggesting an astronomical score on this test.

Based on these numbers, I am thinking that I need to drain the pool and basically start fresh. Because it is a fiberglass pool, I am planning on draining it by approx. 1/4 of its total volume at a time and repeating the process 3-4 times over the period of a week or so. I can also use this time to pull the D.E. filter out and give it a good degreasing/cleaning using the methods I have seen on the forums.

I wanted to check with you guys and see if these steps seem appropriate and if so, if anyone has any recommendations or tips/tricks for me.

Thanks for any info you can provide!

 

[Richard320]

Welcome!

A very pale sky blue is the color you want on the CH test. I use 5 drops instead of 3 with the 10 ml sample so that it's easier to see. The test should go from pinkish to maroonish or lavender, and then to sky blue.

If they've been using pucks, it's easy for the CYA to get that high. Or perhaps someone tried to clear the green before showing the house and used a lot of dichlor "shock". Either way, the solution is a drain and refill.

I think you have a good grasp on things. After the refill, balance it using bleach, then add the salt and give it a day to mix well before turning on the SWG.

 

[msgtdan]

Check out this thread, it could save you some time and money on the water exchange. http://www.troublefreepool.com/threads/52373-Foreclosure-Swamp-in-Pensacola-Florida!/page3 Also you might check with your water supplier as some sewer fees can be waived for a pool fill.

 

[jblizzle]

Welcome to TFP!!!

First, for the FAS-DPD test, use a 10ml water sample so each drop is 0.5ppm ... this will make your reagent last longer and there is no need for a 0.2ppm accuracy.

Sounds like your CH is ~350 You always add drops until there is no visible change and the last drop does not count. It is a fairly faint sky blue end point usually.

Sounds like your CYA is quite high ... so that is the most pressing matter. You can start the CYA test with 50/50 mix of pool and tap water and then read the test with the tube at your waist and your back to the sun outside and double the result to get a better idea ... although I might do a couple of partial drains before doing that as it sounds quite high.

Seems like you are on a good path

 

[Patrick_B]

Something else that may help is adding a couple of extra drop of CH indicator (R-0011L) when you prepare the sample. It will not affect the
accuracy of the test and might help you see a more vivid color change.

Follow the suggestions of others above on the end point.

 

[eGGnog]

Hey all. Thought I would submit a progress report. I have done two cycles of draining and filling, estimating 1/3 of the total pool being drained at a time. My FC is down to 5, CC @ 0.5. CYA is still off the chart, and I don't really understand why. When testing CYA the black dot disappears at the 1.8 ml mark of the small comparator. I assume I need to just keep draining and filling until that number is reasonable.

I also wanted to say that I used the method on the forums for cleaning my DE filter grid and it worked fantastically. The previous owner apparently never added DE after backwashing. He would just pop the top of the filter once a year and hose down the grids. I wanted to get a fresh start on the pool so I used the acid cleaning method found on the forum and now my filter holds rock steady @ 15 psi.

My next step is having a fiberglass repair company out tomorrow to look at the cobalting issue I am having. I am thinking the fiberglass will have to be refinished, but I am looking at that as a good opportunity to start fresh with a pool that is already 20 years old, and maybe even make a slight color change to a deeper blue. After that, I am going to look into self-installing either a 3/4 or 1hp WhisperFLO or an Intelliflo VS & a SWG. I am in Texas where my electric rate is only $0.08/kwh so I am not sure I need the extra up front expense of the VS pump, but on the other hand I am interested in the idea of being able to specify flow rate.

I also wanted to thank all of you guys. When looking for a new home I knew that one of my musts was a pool. I was also very nervous about the steep learning curve that comes along with having that pool. This forum has been my go to source for any and all questions I have had and I always get an answer whether it is from searching through old threads or posting this one, so thank you for being an awesome community and I look forward to learning a ton and maybe someday helping someone who is starting their pool journey like I am now.

Finally, I thought I would share a pic of the pool, because I am pretty proud of it.

 

[bobodaclown]

Good looking pool.

 

[pwrstrk]

Looks great to me !!

 

[mrcarcrazy]

Looks great, what area of Texas?

 

[eGGnog]

North Dallas area

 

[kizerman]

North Dallas area

I went through the same CYA nightmare a few years back. I too drained half the pool and the CYA was still off the charts. I did two drain and refills then decided just not to panic. I stopped with the triclor and diclor and used strictly bleach.

While CYA will not evaporate out of your pool it will splash out and backwash out with regular pool use and since I was refilling with tap water which is CYA free, the levels quickly came down. Once we got into full pool season here, the amount of pool use by the kids and dogs called for a lot of refilling.

Yeah maybe I backwashed a little more often than normal but it came down faster than I expected. Now I find I have to throw a little diclor in once in a while to add cya.

 

[pwrstrk]

Just make sure your testing and keeping track of how much each addition of diclor is raising your CYA level.