Peristaltic pump information moved from Chlorine forum

[fcfrey]

Edit: Just to keep this in context --- this thread evolved to this discussion from the original "Normal "burn" rate for chlorine in a day" thread in the "Using Chlorine and Chlorinating Chemicals" forum and was moved here at my request.

Thanks Richard ----- WOW!!

Since I am injecting continuously with the peristaltic pump I can expect a higher burn off and I am willing to sacrifice the extra to avoid the yoyo and daily carry and dump routine. My system has a 15 Gallon tank which will last about 26 hours at maximum pumping rate (which I should never have to do) and about a week at a normal injection rate. I'm also sure the burn rate will increase as the days get warmer and the rug rats invade. :D

Either way the experiment is going well. With an outlay of <$400 for everything and not having to worry about CYA and lugging the jugs, I think I have a winner.

Here's some images of my system:
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3928.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3929.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3932.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3935.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3934.jpg

[Pool in Carolina Blue]

Thanks Richard ----- WOW!!

Since I am injecting continuously with the peristaltic pump I can expect a higher burn off and I am willing to sacrifice the extra to avoid the yoyo and daily carry and dump routine. My system has a 15 Gallon tank which will last about 26 hours at maximum pumping rate (which I should never have to do) and about a week at a normal injection rate. I'm also sure the burn rate will increase as the days get warmer and the rug rats invade. :D

Either way the experiment is going well. With an outlay of <$400 for everything and not having to worry about CYA and lugging the jugs, I think I have a winner.

Here's some images of my system:
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3928.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3929.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3932.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3935.jpg
http://i129.photobucket.com/albums/p206/fcfrey/DSC_3934.jpg

FC:

How difficult was it too install the necessary equipment?

[fcfrey]

Keep in mind I have been in maintenance and construction for 40 years and have a masters electricians license, so for me it was really simple.

The hardest part was tapping into the switch circuit so that I could energize the power to the peristaltic pump. Beyond that -- drilling and tapping the return line for the injection port was required.

If you have the proper tools, are mechanically inclined, and have knowledge of electricity, self installation is not a problem. All parts were purchased from WW Grainger.

Pump --- 2p304 (includes injection port, tubing and suction line strainer)
Tank --- 2p307
Weather proof plug
Wire
other misc stuff depends on your installation.

I took a lot of time calibrating the pump to create a flow chart etc.

[Pool in Carolina Blue]

FC:

Probably a bit much for me to undertake!

[Steve #1]

fcfrey,
What would it take to get you to do a full "how to" on your setup?

I'm wanting to do something similar. I'm pretty handy, but this is a little out of my realm. The only "how to" I've been able to find is this one (http://www.truetex.com/poolcontrol.htm). While it is very detailed, I'd still like some other ideas for a good setup.

I'm planing on doing this next spring, so I have a little time to work things out. I first have to install the ELK M1G alarm/automation system that will eventually control the pool pumps and chlorine injection etc......

(sorry for hijacking the thread, just wanted to be sure this was seen)

[fcfrey]

I have read, printed, and even called Mr. Kinch about his system. He uses ORP sensors, and a computer running Linux to control his system. Mine is not nearly that sophisticated. My pool manager (Wife) tests daily and adjusts the speed of the pump just like she did when we used an erosion feeder and pucks (before we got educated (here)). :)

I considered probes and controller but the technology is not what I think it should be and the equipment is not cheap. I tried a bunch of different probes (see my old posts) and had poor results. :(

I'm more than willing to do a "how to", but it will have to be somewhere else (not in this thread or forum) --- Possibly in the Chlorine Feeder, Off Topic or China Shop. I'll leave that up to the moderators. It may be better to do it privately.

Another consideration is the multitude of different arrangements in plumbing and systems. I know how mine works down to the pump curves and insulation on the pipes. Having someone follow my directions and mess the whole system up could be disastrous and obviously I am not willing to accept any liability. :eek: :eek: :eek:

AL, Janet, Carl, Watermom ----- your decision. Perhaps you would want to move the last couple posts too ---- I don't care.

[Steve #1]

I'm not planing on going all out with sensors and such.

Using the ELK to control the injection, I can find a good ball park for an average day and either manually adjust it (by computer) from there as needed, or, if i do decide to go all out, make some complex rules to automatically compensate for amount of sunlight etc., but I still think this would just help with keeping me in the ball park.

I'm curious as to what to look for in a pump, and how to plumb it to avoid back flow and such. Suggestions on storage tanks would be nice too.

Don't worry about me holding you liable if something you say doesn't work for me, I know I'm perfectly capable of screwing things up on my own. I'm just looking for ideas for my setup. :)

[fcfrey]

I'll take this a bite at a time so those who are interested can follow. First let me say I am still in the experimental stage. I am still learning so take those things under advisement (this could end up a total flop).

Here goes----

Several things must be determined before you go shopping for the parts and pieces you will need.

First you must know how much liquid chlorine your pool uses during peak periods. You will also need to know the minimum flow needed to maintain a given PPM in your pool.

Your purchase of a pump hinges on these two values, assuming you intend to run the injection system while your circulating pump is running. I circulate mainly during the day and try to keep up with solar burn off. A lot of pool owners use a different philosophy but........ Since there is no burn off and I don't have algae eating the chlorine --- I give the system a rest at night. Choose a pump that gives you what you need in terms of Gallons per DAY minimum and maximum.

Of course you need to be able to test the pool accurately and since I do not believe the labels on the bleach containers, I test each batch I buy. I use the FAS-DPD method using the 25ml sample size when sampling the pool and the bleach batches.

Sampling the bleach is an extra, but until you know how much of what concentration you are feeding it becomes a guessing game if you don't.

My method for sampling my injection solution is as follows:
Using a 1000ml volumetric flask -- fill to 1000 ml with well water or distilled water. Then add .10 ml of the solution mix and test using the FAS-DPD method (the result in ppm equals the percentage in the concentrated solution). I use a syringe from the drug store that is used for the TB mantoux test. It is graduated in .01 ml to 1 ml max -- but any syringe you can get that allows you to accurately measure .1 ml accurately will work.

As mentioned above I used a pump that I purchased from W.W. Grainger. The pump is a Mec-O-Matic VSP-20. It fit my needs, included the injection fitting with check valve , tubing and suction line strainer plus it was not very expensive (< $200). I must say there are better pumps out there (look at Stenner pumps) which are weather proof (Mine is NOT so I had to build a weather resistant box to put it in).

The tank was separate and is also available from Grainger in 7 or 15 gallon size. You need a tank that will hold at least a couple days of solution, is opaque, chemical resistant, and has a large fill cap. It needs to hold enough solution so you don't have to be messing with it all the time, which brings me back to determining what your needs are and what concentration you want to feed. Obviously feeding 12.5% bleach takes a lower flow to do the job but also breaks down faster in the tank if it lingers there too long. I am current using 3% (diluting what I buy as appropriate).

I have been testing the solution when I fill and then again when the tank is just about empty. I do this to see how well it is holding up under the conditions that are present (not in the shade or a cool place) --- so far I have not experienced any significant degradation of my solution which is mixed with pool water (but it isn't summer yet!!). There is a bit of CYA (25ppm) in the pool water but I doubt if it has any effect on the stabilization of the solution. At a feed rate of ~60 oz/hour [3%] running 10 hour per day, you find that to be about a 3 and a half days per tank full (I expect this to change and may have to go to 6% bleach as the demands rise).

That about sums up the prerequisites. If you haven't downloaded the Bleach Calculator DO SO NOW --- You're going to need it!!. Also, search on my old posts and also those from "Hamop78" (I used a lot of his ideas)--You will see a lot of information from Richard (Chem Geek) and others on the subject. --- I'll get into installation next time.

[fcfrey]

Now for some of the installation. A storm is coming so it may be short.

Hooking up the plumbing is pretty straightforward. The peristaltic pump, by its very nature will not back feed. In addition the injection port I used has a "Pop-it" type check valve built in. It works by actually requiring a greater pressure from the pump than on the other side in order to open and since it only goes one way it acts as a check valve. If the tubing comes loose or breaks the only consequence will be to pump the injection solution on to the ground at the rate the pump is set for.

Installing the port was only challenging because I wanted to locate it as far away from the other systems as possible. Definitely as far downstream of other chemical feed devises (erosion feeders etc,). I also wanted it to be out of the way so the port didn't get damaged. The port was 1/4 inch male pipe thread so I had to drill a hole of the proper size to accept the 1/4" pipe tap, in this case that drill size is 7/16". I also chose a location where I had multiple layers of PVC pipe to drill through (actually 3 fitting thickness). This gave a broad surface to tap and seal with Teflon tape.

The tubing to the pump and tank was just a matter of hooking up the tubing.
The only caution is to hook the tubing up to the proper sides (in and out).

Your local building code may require you to have a licensed electrician do the electrical work. Check the code in your area!!

The electrical was only challenging because everything beyond the breaker box at pool side is 220 VAC 2 wire with a ground. The pump was 110 VAC so there had to be a neutral. I have to preach a bit of National Electrical Code at this point. I'm not yelling but ----- NEUTRAL IS NOT GROUND. YOU MUST HAVE A NEUTRAL AND A GROUND. In addition NEC mandates NO OUTLETS WITHIN 10 FEET of the pool. I wanted to be able to unplug the pump and remove it for the winter and had the 10 feet from pool side. NEC also dictates these type things must be on a Ground Fault Circuit Interrupter (GFCI) breaker. This could be a problem if your pump is not on a GFCI (I installed a GFCI breaker on the main line at the house when I put the pool in so I was covered on that aspect. Things become a lot more complicated if you don't have the proper electrical facilities available. I'll explain how to overcome these obstacles if someone cares.

I had to pull a neutral from the box to the peristaltic pump outlet. I used one side of the pump feed after the last switch in the circuit so that the only time the peristaltic pump runs is when the pool circulating pump is running. This avoids building up a concentration of bleach in the return line. There is a switch on the peristaltic pump just in case you want to it shut off.

That's about it for installation so now it's Q&A time.

Next installment I'll touch on calibration and operation.

[Steve #1]

Plumbing the pump sounds easy enough.

I'm glad you pointed out the electrical side. I'll have to take a closer look at what I have there. I'm pretty good with low voltage DC but not so good with the household stuff. I'm going to switch the main pump and booster bump from using timers to connectors at the same time I do the injection. I'll probably get someone with more experience to help me with the electrical.

[Steve #1]

Well, it looks like this is coming together faster than I expected. I'm getting a 20-25 gal chemical drum from work, and Just picked up a Rola-Chem peristaltic chlorine pump on ebay for $32 shipped. Go figure, I finally find a great deal on a pump and it just so happens to be specifically for what I'm doing. I'm going to wait to see what all comes along with the pump before getting anything else, but worse case, I'll need a check valve, injector, and some tubing.

[fcfrey]

Steve,
Glad to hear your project is coming along.

I'll add this post on calibration of my system so you have an idea where to start.

Calibration of Peristaltic Pump:

First secure an accurate graduated cylinder > 200 ml and a stopwatch or other timing device so you can measure how much is being pumped over a period of time.

Start by dividing the speed control of the pump into equal divisions unless it has this done (mine did not). I then started the pump and counted the revolutions per minute and divided this by the number of lobes on the pump to determine how much is pumped per revolution or lobe cycle. Set the pump on each setting and time for 1 or 2 minutes recording how much is pumped.

Use these reading to figure the amount pumped in an hour. I created a spreadsheet to make my life easier. I then verified the calculations over an 8 hour period.

Using the bleach calculator I was able to figure out the PPM increase to expect for a given period of time (assuming no consumption from algae etc.). I did this at night to try to cancel the effects of solar burn off. I found I could predict the outcome accurately using this method.

The next thing I tried to do was calculate the PPM loss due to solar burn. This turned out to be a somewhat fruitless effort because of all the factors (clouds, date, water temp, pump run time, swimmer load, etc.) Needless to say I test very frequently (FAS-DPD method) and adjust the pump to keep the range within Ben's Best Guess Chart for my CYA level (around 22 ppm). After a period of time I was able to come up with some averages to work with.

I have since started increasing the CYA toward 30 ppm, to try to determine the best overall ratio. My daily CL burn off was about 2-4 ppm. if the pool is uncovered all day.

My experiment will continue for a year or two but things are favorable to this point. I may start looking at controllers if the price comes down but so far the cost/benefit ratio is still out of whack in my opinion. Any further questions --- please ask.

[nater]

Hey FC, I like your solar array! Very cool.

I use about 250' of black garden hose coiled up on the concrete when I need to add a few degrees. The BTU output on a hot and sunny South Carolina day is amazingly high....

Cool chlorine feeder as well. I love this home made McGyver stuff :)

[Steve #1]

Well, I got the pump and I'm not sure how it's going to work out. Rola-Chem had changed its model numbers and I couldn't find exact output for the pump I got, but it looked like it was the model for small to medium pools. Unfortunately its output is in line with there model for a large spa or for use as an acid pump for large pools. Output is 225 ML/Hr.

Based on my average consumption and normal pump run time, it should work for the most part.

I'm going to go ahead and set it up to see how it goes. If it can't keep up I'll just switch to a different pump.

[Steve #1]

OK, I'm set for everything except the electrical.

I got 2 60L (~16 Gal) chemical drums from work.

When buying tubbing, I was torn between clear vinyl and black vinyl. The black blocks UV, but would heat up more. I went with the clear since it was cheaper and plan to run it inside some 1/2" PVC I have on hand. This will reduce heat and UV exposure along with giving it some protection from dogs, kids, etc.

I am considering digging a hole and partly berrying the storage drum to reduce the effects of heat. The area where it will be is almost 100% shaded (between a shed and the house) so I haven't decided if it is worth the effort.

I had to buy a tap for my injector. I couldn't get a firm answer from either the hardware guy or the plumbing guy at Lowes if it was the right one or not. What I'm using as the injector is 1/4" MIP. The tap is 1/4" 18 NPT. After doing some research I'm 95% sure this is right, but I got a 1 1/2" PVC coupler to practice tapping just to be sure.

I should have this ready to go tonight.

I don't think it's much of an issue, but I'm going to order a check valve to install at the injector.

Now the electrical. The pool pump and booster pump are 240V and have intermatic timers. Ultimately these will be changed to connectors controlled by the home automation system, but that's down the road.

The Rola-chem pump doesn't have a normal flow rate adjustment. It has a timer that will run for a time (adjustable) then shut off for a time (relative to the run time).

I'd like to set up the injector pump so that it only has power when the pool pump is running. Is it possible (safely) to step down the 240 to 120 after the pump timer?

My other options for electrical are:
Running 140 from my bathroom vanity to the other side of the wall. Possible downsides to this are that the bathroom isn't on a GFCI (which should probably be updated anyway), and the outside wall is brick.

There is a switch and a timer for landscape lighting in the back corner of the yard. I have no idea where it runs from or what else is connected to it. I went to take look at it a bit ago and the ants informed me that it made a comfortable home, but agreed to move out. :)

Any opinions or criticisms are welcome.