# sizing of Autopilot

#### bestlandlord

Without reading thru all the posts again it seems as if I saw mention of buying a larger unit than the advertised capacity which is based on 100%. 100% of what I don't know. If I'm wrong correct me I think Poolsean in one post said everyone advertises this way. So all this to ask if I have a 32000 gal pool should I buy the "60" so the percentage is lower? I think the lower % gives longer cell life but I don't know why. The purchase price between the "48" and the "60" depending where you go is 1-200 dollars. Thank You in advance.

#### JasonLion

TFP Expert
Platinum Supporter
All SWG cells wear out eventually. The larger cell can generate more total chlorine before that happens. Given that your chlorine demand will be some constant, we don't know just how much but regardless of the cell you will use the same amount of chlorine, the larger cell will last you longer. The larger cell can also make more chlorine in a given amount of time, which allows you to have a shorter pump run time in extreme situations, though this limit should hardly ever come up.

Cells are sized for the hottest day with the largest bather load with the pump running 24/7. Since you amost never have the hottest day or the largest bather load you almost never need to run the pump anything like 24 hours a day. I have an SC-60, rated for 50,000 gallons, and I only have 20,000 gallons. So right there I should only need to run it 10 hours. But right now I only run it perhaps 3 hours a day on the lowest power setting, all kinds of leeway.

#### Poolsean

TFP Expert
Bestlandlord,

What I was trying to explain is that the pool volume that a cell is rated for is based upon the maximum output of that cell. The maximum output is based upon 100% output of the system for 24 hrs.
The example that Jason gives is good. If the cell is rated for 40,000 gallons, that is based on 100% output of the cell at 24 hrs of operation. If you're running 100% at 12 hrs, it should be good for 20,000 gallons. If you're running your pump 6 hrs/day, then its good for 10,000 hours. There is a "fudge factor" in the pool volume to be safe. In either case, I will always recommend oversizing the system and getting the biggest cell you can afford.
You get longer cell life, longer warranty, and more chlorine production in a shorter period of time, if needed.

#### bestlandlord

thank you both looks like I will get the 60. I was sure I wanted the Total Control but I read the installation manual and it sounds extremely complicated to set up and "oversee". The keeping ph and orp probes wet at all times part seemed particularly troublesome. When I shut my pump off water drains out of the pipes and takes a minute or so to flow again when pump is turned on. Also the cost of the 2 probes every 2 years is prohibitive. The pool only gets used for 12 weeks at the most each summer. I think I can handle the muriatic acid and regular water testing.

#### JasonLion

TFP Expert
Platinum Supporter
The sensor cell on the Total Control system is designed not to drain when the flow is off even if the pipes drain. And the whole point is to have less to oversee, though there is a learning curve. It is a more complex install and it does indeed cost more.

#### Poolsean

TFP Expert
There is an in between step between just the Digital purifier and the Total Control system. The pH control system. This does not involve the ORP and pH sensors, but only the Digital (#75003) unit, manifold assembly, and the acid tank with chemical feed pump kit.
You would adjust the purifier output like a normal Digital unit. Then you would adjust the feed rate of the acid pump (oz per day, per week or any quantity in between).
Just like you would adjust the Purifier output % in the purifier mode, you would also do the same for the acid feed pump. Test the pH to see if you're at the right feed rate and adjust higher or lower, as needed.
It's not quite the cost of the total control, but does at a bit more automation to your system, without the "complication" and need to oversee the system.

#### bestlandlord

Poolsean I have placed an order with Josh at Saltwater and was reading your above reply to him. It seems as if you are describing a model that he is not familiar with or Josh and I are misunderstanding you. Could you please be more specific as to what I would order from Josh besides the Dig 60 w/manifold. It seems as if you are desribing a model or combination of components that is the Dig 60 with acid control. Thank You again.

#### JasonLion

TFP Expert
Platinum Supporter
A Total Control system has several different pieces. To do automated acid feed without the sensors you would order a TC system but without the chemistry controller, Part#: 75001. You can't use the main controller from the Digital system, you have to get the main controller from the Total Control system, Part#: 75003. Add the appropriate manifold/cell, the acid tank/pump configured for appropriate voltage/frequency, and possibly the aux relay (if you want to control both the acid tank and a pump). The savings should be in the area of 30% over the complete TC system.

There is nothing at their web site explaining this. However, if you slog through the manual for the TC system, here, you can see that the chemistry controller is treated as an optional component.

#### Poolsean

TFP Expert
75003 - Digital control unit for Total Control System
75005 - 220 volt Stenner chemical feed pump with 15 gallon tank
94113 - manifold assembly with SC-60 cell

These are the only components needed, unless you're planning on using the 75003 Digital to control your filter pump.
Then, 75008 will be needed too.

Jason clarified this perfectly.

(ps, thanks Jason)

#### ewsb

##### Well-known member
Autopilot Total system for a 15000 pool

Poolsean

I am looking to use the system on a new gunite pool which has a Intellitouch control system and I want as little maintenance as possible. THe pool will have an automatic poolcover as well. Can you let me know exactly which parts I need to order as I was confused as well.

Many thanks

Sean

#### ewsb

##### Well-known member

Poolsean

Having had a couple of pools before and looking at prices for the autopilot total, it seems that a traditional sal chlorinator only is probably all that is needed for such a small pool - 15000gallons - and then acid can be dealt with manually - any thoughts?

Thanks

Sean

#### Poolsean

TFP Expert
The Total Control is for people wanting bells and whistles or have varying bather loads throughout the day. For pools that get little or consistent usage, the Purifier only system is sufficient.

#### ewsb

##### Well-known member
What salt system would I need for a 15 x 30 rectangular pool

What salt system would I need for a 15 x 30 rectangular pool?
The max depth is 6.5ft

#### Poolsean

TFP Expert
I recommend the biggest cell you can afford. The larger cell will provide more chlorine output, if needed, and longer cell life and warranty.

#### JoshU

In The Industry
Re: What salt system would I need for a 15 x 30 rectangular pool

ewsb said:
What salt system would I need for a 15 x 30 rectangular pool?
The max depth is 6.5ft
We also need to know the shallow depth, however I figured on the pool being 15x30 with a 4 ft. shallow end and 7 ft. deep end (I rounded up) and came up with about 18,500 gallons. It would probably be best to use the SC-48 with your pool because you are so close to the 20,000 gallon point of the SC-36.

Josh

#### ewsb

##### Well-known member
Soft Touch V Digital

I assume from reading that the Digital unit is a more advanced unit than the soft touch?

#### JasonLion

TFP Expert
Platinum Supporter