Installing pool now - questions

[33chad]

Hello. I am new to TFP! This site is great. I’ve been reading for hours each night. This is my first pool so please forgive my ignorance.

I purchased a used AG Doughboy (Tuscany) 24’ round pool that has 48” steel sidewalls, uniform depth – 13,500 gallons. I have a liner coming this week. I buried the pool a little. 12” on one side and 19” on the other as my land is a bit out of level.


Backfill
1) How should I backfill around this pool after I fill it with water?
1a) The water table is not high here, so I am not too concerned about any water sitting yet don’t want to worry about the sidewall rusting. (The pool is all resin except for the sidewall and stabilizer rails). The dealer mentioned pea gravel. I don’t want to deal with that if I ever need to replace the liner. I also can’t imagine I need a slurry for 12 – 19”. I am planning on just backfilling with the existing black dirt. Any concerns?
1b) I thought about some sort of insulation on the outside walls, but I think that would hold water between the sidewall and insulation even worse.

Chemicals
2) I have read through the pool school and can’t find details on how to start out the initial balancing of the pool. I’ve read the seasonal guide, http://www.troublefreepool.com/pool-school/temporary_pool_guide, but think there may be some difference since I have a 1.5hp/2hp pump and 250lb sand filter. My city water is 7.3 pH. I plan to fill a few inches to set the overlap liner and then have the firetrucks come in.
2a) Step 1 pH level = 7.3. I should be good on pH (7.2 – 7.8 range) or should I shoot for 7.5? I will test Chlorine soon (ordering TF-100), but assuming trace - low to 0 in city drinking water.
2b) Step 2 13,500 gallons
2c) Step 3 168 oz bleach (6%) if chlorine is 0. I assume I can skip this based on step 5 (adding dichlor) since it will be too cold for several days. I will have bleach on hand for each day after.
2d) Step 4 add 28 oz of Borax to get up to pH7.5. I assume ph 7.3 is good enough and I can skip this for now, but will monitor daily. Dichlor (pool shock) is 1lb per 2,000 gallons. So 13,500/2,000 = 6.75 lbs of dichlor.
2e) Step 5 - the first four days add one ounce of dichlor for every 500 gallons of water (13500 gallons /500 gallons = 27 oz) * 4 nights = 108 oz of dichlor. (108 oz/16oz/lb = 6.75 lbs). Then stop!
2f) Since I have a larger filter and pump, do I need Polyquat 60?

Theoretically I only need 6.75 lbs of dichlor for the filling. Then some bleach for chlorine and either borax or(baking soda after that, pending other issues, right?

Pump
3) The pool came with a Doughboy 2hp pump and a 1.5hp Pentair Dynamo high performance pump. The Doughboy has a timer. The timer is broken, but the pump still works. That’s why they bought the Pentair. The Pentair doesn’t have a timer. I haven’t read through calculating pump times yet so not sure if one of these is better for my setup and if I need to run 24/7.
3a) Please suggest a pump for my setup.
3b) Also do I need to run 24/7?
3c) Do you just buy a cheap timer if not?

Filter
4) Aqua Star high rate 250lb sand filter. 22” diameter tank. 2.6 sq ft of filtration. 35 PSI max working pressure. 55 GPM Filtration and Backwash flow rate. #20 silica sand.
4a) Do I need to buy pool sand or does #20 silica sand translate to something like masonry sand? I am going to be at the sand pit anyway to get sand for under the pool, so thought I could grab some if it is ok.

Thanks so much for all the valuable information and for answering my questions.

PS - I initially wanted to go SWG and have read many comforting inputs on this site, but was hesitating due to all the manufacturer warnings. I was close to going that route, then I read on this site that keeping your pool properly balanced will avoid the negative connotations of using straight chlorine.

 

[duraleigh]

so I am not too concerned about any water sitting

but rainwater and splashout will sit in that hole you dig and make a mess unless you give the water a good escape path. Pea gravel would be excellent for that.

I am confused about your pump situation....do you currently have two functional pumps? Surely they are not both hooked up.

Your filter seems about the right size for the pool. You cannot use masonry sand. You must use pool sand because it is clean.

 

[33chad]

Thanks for the quick response.

but rainwater and splashout will sit in that hole you dig and make a mess unless you give the water a good escape path. Pea gravel would be excellent for that.

My concern is if I use dirt for backfill, will it rust the coated steel sidewalls? I am hoping this is not an issue. As far as a mess, I planned to finish it off with some mulch and plants. I don't want to use pea gravel as I assume I will need to remove that when I need to replace the liner so it doesn't cave in the sidewalls. I could put in some perforated tile sloped at the bottom and run it out if necessary.

I am confused about your pump situation....do you currently have two functional pumps? Surely they are not both hooked up.

Sorry. Let me clarify. I have two functional pumps. I am trying to determine which one to use. The previous owner purchased the Dynamo to replace the Doughboy pump because the timer broke on the Doughboy. I don't even think the Dynamo has a timer, so either one could be used, especially if recommended to run the pump constantly. If not, should I put these on a separate timer or manually turn on and off?

Your filter seems about the right size for the pool. You cannot use masonry sand. You must use pool sand because it is clean.

That's what I figured, but wanted to ask. Thanks!

 

[33chad]

Hello.

After 33 hours of filling, my pool has reached the return jet/skimmer level tonight!! I need to attach hoses to pump and filter tomorrow and then continue filling about 6" of water. I have not added any chemicals yet, but would love if someone can read over my original post and doublecheck my chemical plan. I purchased straight CYA (liquid, not solid) and also Dichlor. I saw that some people recommend using cya over dichlor to avoid confusion. I am fine with either approach. If I use CYA, when can I start adding chlorine? If dichlor, it has chlorine in it already, so I will start getting algea protection right away. Since the CYA is liquid, how do I go about dispensing it as instructions on this site talk about slwoing adding to not hurty vinyl?

Please note that I won't be able to run the pump for about 6 more hours after hooking up pump and filter since the water raises about an inch an hour. I won't be able to hook these up until after work tomorrow, so it will be another night. should I pour some chlorine in now and try to "stir" it up somehow?

I am late in hooking up the pump as I have lots of backfill amongst other work to do and didn't get as the pool fill outran my other progress. I was hoping to not hook up the pump until I was done backfilling, but I think I need to get some chemicals in the pool soon.

PLEASE assist with chemical suggestions! Thanks.

 

[PridgNYC]

Add chlorine and the CYA now. Pour it in front of the fill hoses, and it'll dissipate just fine.

 

[33chad]

Thanks. Even before I have the water high enough for the pump to run? Add all liquid CYA at once?

 

[33chad]

oops. I was wrong. My CYA is in very small granular form. I can tie in a sock and hang, but should I wait for until I have the pump on? Also, Dichlor is cheaper than CYA, and I can return either, but want to do what is best at this point.

Thanks again.

 

[duraleigh]

Your pump really should be running before you add chemistry. If not, you must "mix" it manually to prevent over-concentration.

Do you know how much of each you are going to put in your pool?

 

[33chad]

Thanks Duraleigh. I think I know how much to add. My first post has this listed out. Do you agree? Any suggestion on cya vs dichlor?

 

[duraleigh]

Any suggestion on cya vs dichlor?

I have never been a fan of dichlor. Moving two parameters at once doesn't seem as viable as adjusting each separately. I am not aware that it is cheaper by enough that matters but I think it is important to dose and test carefully when you are first starting up.

How are you testing?

 

[33chad]

Thanks again.

I didn't end up getting the TF-100 yet, but picked up the HTH 6-Way Test Kit. I know my city water is currently at 7.3ph. I haven't tested for CYA or chlorine yet. I assume city drinking water only has trace chlorine and no CYA. Should I test these first or are these assumptions good?

If I need to do the CYA and chlorine separate, then how do you propose I handle this? Do I do the CYA first or the Chlorine? How quickly do I let the disperse the CYA? I know dichlor is a 4 day process but it is releasing chlorine simultaneously. If I need to do CYA first and if it too is a 4 day process, then I have a few more days without chlorine. Will this be an issue? If I add chlorine first, then since you can add it all at once, it seems like I am almost still moving two parameters at once, since I will go right into adding CYA.

Sorry for all the questions, but I really appreciate the help! I am so new to this.

 

[duraleigh]

Your assumptions about CYA and chlorine in city water is correct.

I would dose some bleach dispersed around the pool tonight....stir it around a bit....about 1 gallon. (just for insurance)

Get your pump running ASAP.

Add CYA dosed correctly to get to 40 ppm. Put it in a sock inside the skimmer basket or insert the sock in front of a return so the water is flowing over it. For calculating purposes, assume the CYA is in your pool even though it will not show up on a test.

Now, pump running, add enough chlorine to get to about 5-6 ppm or so.

That should do it. Post complete test results when that is accomplished.

 

[33chad]

Great. Thanks, Dave.

I hope to have the pump running tonight. Even if I have to bypass the sand filter. I haven't been able to backfill around the pool yet and don't want to move the 250lb sand filter multiple times.

I assume I fill a sock up as much as possible and keep refilling till I use up the recommended amount of CYA. My 13,000 gallon pool calls for 4.3125 lbs (69oz). I have a 4lb container, so I will use up that and then test in a week or so.

 

[33chad]

I bypassed the sand filter and am just running the pump. Sock of cya is in the basket. I put in slightly less chlorine than required. I will test chlorine tomorrow.

Thanks!

 

[duraleigh]

Good to go. Keep your FC up around 3-5 and get the rest of your pool finished up.

 

[33chad]

1/2 of the cya has been dissolved and I put the other half in the sock this morning. My pH is 7.2. The chlorine is 5ppm. What other test results do you need at this time? Can all the rest be tested while the CYA is still in flux?

Since we are finally getting some rain, it will delay the rest of my dirt work. I would prefer to not hook my sand filter yet as I can't move it to the final location yet, but can do hook up for now if needed. Does this cause any concerns? Does the filter just remove particles?