HM TDS-3 home calibration solution!

I'm posting this to help solve the problem of calibrating the HM TDS-3. It's calibrated from the factory but it can go out of wack. I went to the hydro store and I bought some calibration fluid. The store owner told me that the Hanna 1100ppm soultion works just fine. Boy was he wrong. I calibrated it with the Hanna solution and it was way off. First off the HM TDS-3 works great and it's cheap. The problem is that most meters use KCL calibration solution. KCL is what is used in the Hanna solution. The HM TDS-3 uses NaCl, that means you must use NaCl NOT KCl! Also 1100ppm is way to high for our hobby. The ppm needs to be calibrated in the mid 350ppm range. Calibrating it at 1100ppm even with NaCl will cause an inaccurate calibration. I bought the HM digital 342ppm factory calibration fluid. After several batches of homemade solution I have a recipe. Now to calibrate your meter at home use:

12 cups of distilled water (PPM must be near zero)
0.5 gram of Morton salt (1/2 gram)
Throughly mix and set temps to 77 F
The PPM will be close to 350ppm (My solution is dead on at 350ppm)
This will allow you to get your meter within an acceptable range.
Make sure your scale is accurate. Place a nickel on your scale. It should read 0.5g if not don't use it.
If measured correctly the solution will be within 340-360 range.

Pos rep given for this simple yet dead on accurate solution! The less I need to show my face at the Hydro store, the better I feel. Maybe im paranoid but I feel like the Hyro store people are in cahoots with the local law inforcement. I know that sounds wierd but when i've called the store to make sure they have what I want before driving over there, I swear im being recorded from the owner's machine. And I hardley ever see people there but they are always doing good business with their merchandise.

There was a thing on TV that I saw. The hydro stores are not involved, they want your money. What LEO does is they post up in the parking lot at the hydro stores and write down every license plate. They use your license plate to get your address and then they come to your house. Some towns and cities are anal about growing. Even if it's for cancer patients. If your paranoid take off your plate or use someone elses car.

Man I never thought of that. I bet im already figured out too. GOOD THING im growing ONLY what my state allows as a legal crop. Ive gone once or twice in my car and with my luck, I probably parked right infront of the "spy", lol! With that said, I dig your method. I hate giving money away to the hydro dude. He's a sales man to the bone, as he should be I guess? I wonder if there is a cheap way to get my PH meter dialed in with a DIY method like you have? If you know one please let me know. Wish I could pos rep you again but it wont let me do it twice on one thread, but share the love if you havent already, bud! Thanks in advance.

Sparkletts drinking water has a PPM of 11. Will that be good enough or do you use a certain type of water thats closer to zero? Please let me know....

Distilled water from walmart has 0 ppm.

To set PH you would need a PH of around 4.0 and a PH of around 7.0 You have to set it for both PH because we use both numbers inbetween.

I retarded.....or I missed something here??????? I dont understand? I have a milwaukee PH meter. I want to know how to colab it but I think I missed something here. My meter is off the mark. I have distilled in a cup. Whats my next step brother? Thanks in advance.