# New to School

#### stakeman

##### Well-known member
Hello Everyone,

I've spent some tome reading the forums and just started posting my build on the pool/spa build & remodel section. At one point I've seen some formula for determining pool size in gallons. I believe it had something to do with average depth and some thing else. I've tried to find this thread again to no avail. When the time comes to fill the pool I will check the starting point of my water meter. I have a couple of easy questions for you regulars. When useing the BBB method will this have any adverse effects on my new plaster? Also, my PB upgraded my pump to a 3 hp, will this cut back on my run time? or am I limited by the volume allowed by the 2" return lines ? Is he really doing me a favor, or will I just see a higher electric bill?
I'm putting in a 97' perimiter, IG gunite, SWG, Depth ranges from 3' to 6'. No spa.

thanks,

Dave

#### Poseidon

##### Well-known member
stakeman said:
Hello Everyone,

I've spent some tome reading the forums and just started posting my build on the pool/spa build & remodel section. At one point I've seen some formula for determining pool size in gallons. I believe it had something to do with average depth and some thing else. I've tried to find this thread again to no avail. When the time comes to fill the pool I will check the starting point of my water meter. I have a couple of easy questions for you regulars. When useing the BBB method will this have any adverse effects on my new plaster? Also, my PB upgraded my pump to a 3 hp, will this cut back on my run time? or am I limited by the volume allowed by the 2" return lines ? Is he really doing me a favor, or will I just see a higher electric bill?
I'm putting in a 97' perimiter, IG gunite, SWG, Depth ranges from 3' to 6'. No spa.

thanks,

Dave
First, off, grats on the new build.
I can only help with the volume question. Note that true dimensions for the shape of the bottom is needed for an accurate calculation. Anyway, I estimate 18,977 gallons. I will say that a 3 hp pump might be overkill, but what do I know? Btw you can download my calculator in my sig (if you have Excel), or use JasonLion's html calculator. I don't have a link for his, maybe someone else does.

#### Rangeball

##### Well-known member
Stakeman, initially, 3hp sounds like WAY overkill for that pool size, but I have no idea what else you might be running.

Using the bleach calc, and figuring a 25' square pool (your 97' perimeter divided by 4) with an average depth of 4.5 (3+6/2), gives about 22,000 gallons. My pool is 18,350, and I'm looking at a 3/4 hp pump being plenty good.

Depending on your max filter GPM, 3 hp may actually damage your filter. I'm having a hard time imagining why you would need this big a pump. Others should add input soon, but if it's not a done deal yet, I'd sure do some homework, quickly.

Perhaps see if maybe he'll upgrade you to a smaller 2 speed pump

#### JohnT

TFP Expert
If you don't have any water features etc, you are enormously oversized on the pump. You could get by with a 3/4HP, but maybe a 2-speed is the best answer.

#### JasonLion

TFP Expert
Platinum Supporter
A 3 HP pump will reduce your required pump run time, but even with the reduced run time it will cost more to operate. The pipe diamiter does affect the total water flow but there is no hard upper limit. A larger pump will result in a higher flow rate, just not as much higher as the extra electricity it uses. Generally you only use a pump that large if you have a spa with extra jets or several different water features that you want to run at the same time.

BBB is just fine with a new plaster pool, but it can be more convienent to use trichlor pucks for the first month or so. With a new pool you need to add chlorine, CYA, and lower the PH, all of which trichlor will do (or help with). You still need to do all the things you would usually need to do with new plaster in any case, keep the PH from getting to high (curing plaster will constantly raise the PH), brush the plaster frequently, etc. Your builder should tell you about all that.

#### stakeman

##### Well-known member
Man you guys are awesome! thanks for all the input. As far as the 3 hp pump goes, I'm with you all on the overkill. The electrican is due out here soon so I hope to talk with the PB first.

Dave

#### Rangeball

##### Well-known member
Want some ammo? Look up the max gpm flow rate for your filter model. Calculate your expected flow from the 3 hp pump.

Relay your concern, unless you have a really big filter

#### stakeman

##### Well-known member
Ok here is where I'm at. I spoke with the PB about my concerns, he said with the water features (which include 3 bubblers, and 2 sprayers) and the pool size he decided to go with the bigger pump. From what I've seen thus far he doesn't cut corners, and judging from the Hayward package he went with I'm satisfied. The extra money is coming out of his end anyway, I just hate to pay the extra power bill if I don't have to. The filter is a big one, it's the Hayward swim clear C5025 cartridge with a 150 gpm flowrate. Depending on the pipe size, 2 1/2" on mine and the head pressure this pump shouldn't be a problem. I'll post more info as I get it.

Dave

#### JasonLion

TFP Expert
Platinum Supporter
3 HP still seems like a bit much. It sounds like the filter and plumbing can handle it though. You can save a great deal on electric costs over the years if you could get a two speed pump. Running on low speed will be fine for filtering, and if you want the bubblers and sprayers to really go you could turn it up to high. Electric costs will be about half on low speed compared to high speed.

#### stakeman

##### Well-known member
I'm with you on that! My builder seems pretty adament about the bigger pump !! It's hard to argue with someone in the biz...I know I'm the one who will be living with it in the end. I'm trying gentle persuasion for now, I like the subs coming out to work on my pool. Thanks again for all the input....

Dave

#### stakeman

##### Well-known member
Decking finished today!! Spray deck and plaster to go.. PB says mid week...The PB is going to do the start up and give me lessons ect for the first month, once a week. That being said; I'd like to use the BBB system..........

Is there anything I need to avoid when the PB initally starts dumping chems in???

Any thing else I need to know upfront, before it's too late??

Thanks,

Dave

#### JasonLion

TFP Expert
Platinum Supporter
It is usually a good idea to go along with what the builder says for the first month at least. If your builder vanishes and isn't doing anything then worry, but if they are showing up and paying attention to the water I would go along with them at first. There are at least two different ways to start up a plaster pool and it is possible to get into trouble if you don't understand which approach they are using and try to correct things to match the other approach. You also don't want to do anything which will impact your warranty. It is often worth doing some silly things to keep them from being able to say you failed to follow directions and they won't honor the warranty.

Beyond the normal care for a pool you should expect to need to brush the pool frequently and add acid frequently for the first while. Starting a new plaster pool on trichlor can work out very well, since you need chlorine, CYA, and PH lowering at first all of which trichlor provides.

While that is happening, get a good test kit and practice using it. Also read The Stickies section of this site, there is a link in the sub-heading on each page, particuarly the first one on BBB and basic chemistry.

#### stakeman

##### Well-known member
I've read and re-read the whole BBB principal. I am 100% convinced this is the system for me. But as you stated above the PB wil more than likly have different ideas. I also agree I feel somewhat obligated to not mention the whole BBB thing to NOT void out my warranty !! I appriciate the input and will be back in the next few weeks with some numbers for you all to crunch. To be honest I feel like a complete idiot when it comes to this stuff and look forward to learning this and helping out others in the future. I can't tell you all how much I appriciate your help! Big THanks Lion..........

Dave