Pentair 521377 Intelli pH Canister with Controller

5/12/2016: I purchased this to better maintain pool pH during the vacations I take, typically two weeks long. Amazon Prime delivered in two days without fuss. My 14,500 Gal. pool was resurfaced (pebble) and converted to salt in 2011 with all new Pentair equipment, including a Pentair IC40 chlorine generator and an Easy Touch control system. Installation was straight forward, and the IntellipH and IC40 have operated as expected for a few days now. I'll provide updates to this review to see if issues raised in other reviews happen to me. The installation instructions were a little sparse, so here are some suggestions that were not covered:(1) For stability, I mounted the canister to an 18" square, 2" thick cement stepping stone using four 3/16" X 1-3/4" long "TapCon" cement screws, available from Home Depot. Surprising that the installation manual was silent on this important safety step.(2) Be very careful opening the parts bag that contains the saddle clamp and other parts. There are small grey compression fittings that are essential for leak-proof connections for the acid tubing at the pump and canister. Again, no mention in the instructions of these fittings, nor how to use them. Place the nut, then the compression fitting with the tapered end of the fitting towards end of the tube, then tighten the nut to its mating fitting on the pump. The nut at the saddle clamp has a built-in compression fitting, so no grey fitting here.(3) I suggest turning on the pump to make sure everything is operating correctly before dumping in any acid in the canister. I put in three gallons of acid, and the level was 9/16" higher than the 3 Gal. mark on the side of the canister. A fourth gallon would have overfilled the canister, so take care.(6/3/16 Update)(1) To set up the acid %, I purchased a THZY digital pH pen tester from Amazon (see my review there), and calibrated before each test.(2) I've now homed in on 78% as the proper setting to maintain my pool's pH very closely. I run my pump 3:15 hours each day, so I get 21 doses of acid per week, delivering a predicted 34.9 Oz. of acid from the Canister (I use Leslie acid which is 31.45% HCL--note that Home Depot and Lowes acids are about half as strong). This seems to be good here in LA, but it might vary in other parts of the country. If you want to try this percent as a first guess, multiply 78% by your # dispenses/week, divided by 21, and then multiple by your pool volume divided by 14,500 gallons, which is my volume. If you get a number bigger than 100%, then you have to lengthen you pump on-time.(2) Both the acid canister and the control box are plastic, and I was concerned about UV degradation, since my equipment is open to the sun. So I sewed up some covers using Sunbrella Canvas to protect them. Sewing is my hobby. It would have been nice to have covers included.

I was really looking forward to not adding acid manually but when I received this unit and unpacked it is when I determined that you can only use it if you have a Pentair CL cell power supply or power supply from one of their total automation systems. It has a custom plug and takes 42VDC input.It looks like a decent unit so I didn't want to give it 1 star, but it was in fact useless for me. No issue with the return - thanks Amazon.

UPDATE 04/22/2015: After working flawlessly for a year, this unit has developed two issues almost simultaneously:1. Tubing inside the pumphead has cracked and leaked acid all over the concrete pad ($35 for new pumphead)2. One way valve inside the injector has disintegrated and clogged up the port ($20 for new injector)Outcome - acid all over the place, cloudy pool water and PH of over 8.0. Reading feedback from around the internet it seems that the pumphead and the injector both last for about 8-12 months, after which they should be replaced.Therefore:1. Pentair should have informed customers up front about the need to replace maintenance parts at 1 year interval (minus a star)2. At this price, I would expect unit to work for at least 2 years before it needs any servicing (minus half a star)3, Good luck getting any support from Pentair if you are DIY and installed it yourself (minus half a star)Apart from that, the unit works great when it works. Just stock up on replacement parts and be ready to service it every year (maintenance is about $55/yr).Original Review: Hardest part about installing IntelliPh was drilling holes in the brick. Apart from that I just hooked it up to IC40, filled the tank with acid and dialed in the dosing %. Have not touched pool chemicals since install.Update 8/5/2015: New check valve lasted about 3 months before duckbill inside it has melted again. Instead of buying a brand new injector for $20, I found that I can just order a five-pack of duckbills (Part# MCCVDB0 by Stenner) for $15 ($3 a pop). I am planning on replacing duckbill inside the check valve every 2 months during swim season to be on a safe side.Bumping review up to 4 stars because even with all this hassle it is still worth installing IntelliPh rather than having to manually add acid to pool every other day.