Where to Start

[eatdairy]

Okay I have been browsing the pool school and some of the different topics in the just getting started forum. I have been taking care of my pool for a year now. In the past I had used the "test Strips". In the past few weeks I noticed some darker patterns on the floor of my pool. This has prompted me to do more research and get my pool into shape. I am assuming that the dark areas are black algae in the crevices of the pebble tec. Currently I use 3" stabalized chlorine tabs...mistake i think...The current test numbers that I have are
fc 5
tc 5
ch 150
cya 99
TA 80
PH 7.6
copper 0
Iron 0
Phosphates 300

After utilizing the calculator It appears that I need to replace some water. Once i have replaced the water I need to re-test.

The pool is crystal clear with no off odor.

I did shock 2 days ago with Aqua Chem (active ingredient Sodium dichloro-s-triazinetrione) From Costco

My main question is where do i start? Drain the pool by half?

Thanks

 

[duraleigh]

The CYA is the only reason to drain your pool but that is reason enough.....it makes your pool almost unmanageable

A test result of 99 implies thats as high as the electronics go so it may be higher.

Anyway, it's a direct reduction....if you drain 50%, your CYA goes down by 50%.

We usually suggest draining in thirds to prevent excessively low water levels.....drain 1/3, refill, and test. drain 1/3, refill and test, etc. etc.

Don't be surprised if you have to drain more than 2/3 of your pool to get CYA down to a manageable level of about 50 ppm.

The dichlor and pucks all contribute VERY quickly to your CYA buildup so you will want to stop using both when you get to 50 ppm.

Relying on Pool Stores for testing and advice is quite precarious.....you should get your own test kit...one that has the FAS/DPD chlorine test

 

[Isaac-1]

Right now you need to do at least 2 things, lower the CYA (drain and replace at least half your water, you may want to do partial fills as Dave suggested, or if water is expensive where you live you can use the tarp method. Which involves getting a big plastic tarp that is larger than your pool (the clear plastic dropcloth type can work)and fill fresh water on top while pumping out high CYA water from under the tarp. In many areas water is cheap enough that the difference is not worth the trouble and cost of the tarp.

The second thing you need to do is kill whatever is growing in your pool, the easiest way to do that is to get one of the suggested test kits (see my signature) and follow the shocking your pool instructions in the pool school link.

Ike

 

[eatdairy]

How do you determine what your optimal CYA level is? I am in the central valley with pleanty of sunlight on this pool. We have had pool temps of at least 70 and now up to 85 already.

 

[Isaac-1]

For sunny areas around 50 ppm CYA is generally suggested if chlorinating by hand

 

[eatdairy]

okay did a 50% ish drain on the pool.

These are my new numbers
cya 45
fc 1.5
tc 1.5
br 3
ph 7.2
alk 70
ch 130

Whats the next step reccomended ? Shock? I did notice that some of the pepple tec is flaking off (low CH) when I drained the pool. I do still have what appears to be black algae in the floor on the downward slope of the deep end. Not 100% sure, however it does appear different looking than the rest of the pool.
Whats the difference between the DPD-FAS and the DPD kit? I thought I was picking up the reccomended kit and realized mine is just the DPD kit.
Really appreciate the input.
Eric

 

[Richard320]

Whats the difference between the DPD-FAS and the DPD kit? I thought I was picking up the reccomended kit and realized mine is just the DPD kit.
Really appreciate the input.
Eric

You've been Pool-stored. It's almost universal here that people go in and ask for a FAS-DPD test kit and get sold the DPD tester with the assurance that it's the same. It's not! The FAS-DPD test uses a powder and drops. You count the drops until the water is clear. It can tell you FC to .2, although most of us use the smaller sample, which is accurate to .5. Lucky for you, you can order just what you need by itself.

Your FC is too low for your CYA. It should never drop below 4, and when you dose it, you should aim for 6. Every day.

If you have black algae, you'll need to go even higher. See what happens when you maintain the right FC level for your CYA and brush the spots often with a steel pool brush.

The low CH is easily fixed. You can shop for the plain Calcium products, or get it as Cl-hyp pool shock, which will also let you chlorinate at the same time.

Back to Pool School with you

 

[eatdairy]

I am running a tr-100c sand filter. Is there a GPM minimum for this filter to be efficient?
Right now I am trying to determine the run time and at what rpm for my pool.
The manual says the capacity is 74gmp
I am assuming that If i choose to run my pump at a lower rpm for a longer run time I will still get a sufficient filter...
Currently I am running 8 hour cycle 4 days a week at 1500 rpms which is supposedly (60gpm)