Question on ph controller....

[Lonewolfblue]

When purchasing a ph controller, the SMS122, it comes with a power plug in, cal. screwdriver, ph packet, and probe.

1. Is there anything else I need to get?
2. How long does the solution packet last?
3. What's the best way to calibrate it?
4. Should I purchase extra probes?

 

[CGGorman]

1. I would get the cleaning solution too.
2. One use
3. Dip the probe directly into the solution packet
4. No

You need to recalibrate every couple months. You can use RO water for this. Calibration is very simple and quick.

 

[Wizzard~Of~Ozz]

When I calibrated mine I used vinegar and the 7.0 solution.

First put it in the 7.0 solution, adjust the screw marked "cal", then I put it in vinegar and used the hidden screw on the back to adjust to 2.8, then shook it off and back into the 7.0 and re-calibrated it to 7.0, then back to the vinegar and it read 2.8, perfect..

The hidden screw on the back adjusts the "slope", otherwise 7.0 will be correct, but what it says is 6.8 could be anything. You can buy their solution or you can use pure distilled water and vinegar to make the adjustment..

The instructions do actually show having to adjust the slope, mine was off by 1 point, so for every PH drop of 1, there was a lost acurracy of .2 (6.0 was actually 6.2..) etc.

 

[sherry]

clarify please... pure distilled water is 7.0 and vinegar is 2.8?

I tried to calibrate with only their 7.0 solution. I'd like to fine tune without buying more of their solution.

 

[Wizzard~Of~Ozz]

http://www.adbio.com/science/analysis/ph_scale.htm

You can use anything on that scale, tho bleach and caustic chemicals tend to be bad.. so I used vinegar. If you read the instruction on calibrating the meter it does state you will need another "solution" of PH 4 to adjust the slope, but most seem to skip this step resulting in anything but PH7 being inaccurate. PH 2.8 will be very accurate aswell. (moreso then PH4) just make sure you use white vinegar. And no need to buy any of their soloution except maybe cleaner if you feel swishing in distilled water to be "not enough"

 

[MarcoDaVinci]

You should calibrate with a pH7 solution every week or two, but you should NEVER have to touch the slope, unless your electrode is getting old.
Tkae your time to calibrate, make sure all your liquids are at room temoperature, and give the electrode time to react.

If you want to verify that your slope is correct, adjust the pH 7 first.
Next, here is the scoop :
The pH of Coca-Cola (regular) is 2.7
So if your probe indicates anything between 2.5 and 3.0, you are fine !

 

[Wizzard~Of~Ozz]

Sorry Marco, I'm talking about initial setup.. the slope needs to be set as it's not set from the factory (and certainly not for the probe that is sold with the unit). It should also be adjusted if the probe is replaced. Also adjusted if it was never set from day one.

 

[Lonewolfblue]

I agree with Wizzard. I like that aproach on calibrating it, and I do have a new bottle of white vinegar as well. I just need to get a couple packets of the ph 7.0 solution. One comes with the meter, but will need a couple for testing down the road.

 

[Lonewolfblue]

Well, I got my controller today. I calibrated it, was pretty darn easy.

Just 1 quick question. The set point is where you want it to turn on and off, right? How far does it go each direction before it switches to either on or off? I checked my settings, and here's what they are.

Ammonia 0ppm
Nitrite 0ppm
Nitrate 10ppm
Phosphate 1ppm
ph 6.4
kh 60 / 3.4 degrees

I have my setpoint at a ph of 6.5. Is that where I want it?
Or should I go a little higher or lower?
What's your recommendations?
How am I looking for everything else?
I will be letting the CO2 run 24hrs, now that it's on the ph controller.

 

[ringfinger]

Your pH will hit 6.7 before the controller will kick on the Co2. Kinda lame, but it's just something to take into consideration.

 

[Lonewolfblue]

I got the Milwaukee SMS 122. Forgot to state that in the above.

 

[Wizzard~Of~Ozz]

yes, it has .2 swing. so 6.5 will creep to 6.7 then kick on and drive it back down.

 

[7Enigma]

MarcoDaVinci,

I don't see how using a carbonated beverage will give accurate results. Unless you open a new can/bottle every time I'm sure the pH will be different between a bottle that is 1/2 empty and has been in the fridge for a couple of days and a new can.

I like the vinegar idea much better.

 

[CGGorman]

You would definitely need to open a new bottle/can every time. I don't need a reason to open a can of Coke, so that's no problem for me!

I still like the vinegar better for calibration. I'll drink the Coke while I calibrate in vinegar...

 

[ringfinger]

One more question...why does it require a second calibration screw for the pH 4 solution or vinegar? Why 2 screws? Does it require more fine tuning with a lower pH?

 

[Wizzard~Of~Ozz]

One is to set the "standard" point, or a "zero screw", the other adjusts the scale. so from zero down 3PH requires you to tell it that distance on the scale is -3ph, then it knows how to interpret the different readings.

 

[Lonewolfblue]

One more question...why does it require a second calibration screw for the pH 4 solution or vinegar? Why 2 screws? Does it require more fine tuning with a lower pH?

If you just use 1 point of calibration, then the only reading you know for sure is accurate is that 1 reading. So you really need 2 points. As Wizzard said earlier, the 2nd one is the slope. If you callibrate the 7.0 as being 7.0, then you callibrate the slope at 2.8 (White Vinegar), then you know everything in-between is going to be accurate.

 

[ringfinger]

Oh makes sense... I should THINK some more before I post. Thanks guys.

 

[Lonewolfblue]

Another question. If you turn off the controller using the on/off button, when you turn it back on, do you need to recallibrate it? I turned mine off to do my filter maintenance, and now my reading on the meter is way off compared to my AP kit.

 

[Wizzard~Of~Ozz]

No, you should only have to calibrate it when the probe get's dirty or when the probe is replaced. I check mine against the 7.0 every couple of weeks and it's been dead on each time.