Water PH and solutions

First grow. 12 days in had some problems this morning but made the transplant today and she seems to be doing a lot better.
I am using straight tap water and I ordered a PH tester and it came in at 7.81 and 8.24. Two very different readings because the tester is a piece of shit. Going to return it and get another one. Either way I'm under then impression that Ph is too high.
Was thinking of using distilled water but then I'm not sure if it would be missing out on any nutrient's that the tap water would usually provide.
There's been some yellowing of the cotyledons and even the first set of leaves not sure if that has to do with the water.
Had some LEDs way too close since this morning. I have them higher now and it was in a Pete moss jiffy pellet
If there are products to get my water to the right PH please suggest

Ill attach a photo of how my seedling is doing so please don't hesitate to comment any information that you think is even remotely useful, I need all that I can get.
Thank you all in advance.

Did you use calibration fluid to make sure the pH tester was calibrated correctly? I end up recalibrating mine every week to two weeks.

Either way that water IS too high for pH. If you're running in soil, you really want to be in the 6pH range, a little lower if it's coir.

So, it sounds like you can use some pH Up/Down for your water as well.

LeastExpectedGrower said:

Did you use calibration fluid to make sure the pH tester was calibrated correctly? I end up recalibrating mine every week to two weeks.

Either way that water IS too high for pH. If you're running in soil, you really want to be in the 6pH range, a little lower if it's coir.

So, it sounds like you can use some pH Up/Down for your water as well.

Click to expand...

I’m using coco with perlite I calibrated with the solutions perfectly I think the 7.8 ph reading is more accurate. Because the 8.3 came after testing a bunch of different waters and mixtures of waters. I cleaned after each test as well. Directions said may need recalibration after frequent use. I read that after I threw away the calibration liquid.
Thanks for the response

Enough to last you a while. pour some out and then return it to the container.

...Up and Down:

LeastExpectedGrower said:

Did you use calibration fluid to make sure the pH tester was calibrated correctly? I end up recalibrating mine every week to two weeks.

Either way that water IS too high for pH. If you're running in soil, you really want to be in the 6pH range, a little lower if it's coir.

So, it sounds like you can use some pH Up/Down for your water as well.

Click to expand...

You think this would work?
Cheapest option but marketed for fish tanks obviously lol

LeastExpectedGrower said:

Biopharm pH Buffer Calibration Kit 3-Pack | 250 ml (8oz) Bottles | pH 4.00, pH 6.86 and pH 9.18 | NIST Traceable Reference Standards for All pH Meters: Amazon.com: Industrial & Scientific

Biopharm pH Buffer Calibration Kit 3-Pack | 250 ml (8oz) Bottles | pH 4.00, pH 6.86 and pH 9.18 | NIST Traceable Reference Standards for All pH Meters: Amazon.com: Industrial & Scientific

www.amazon.com

Enough to last you a while. pour some out and then return it to the container.

...Up and Down:

https://www.amazon.com/gp/product/B000BNKWZY/

Click to expand...

Great thank you

Nilspoulsen said:

You think this would work?
Cheapest option but marketed for fish tanks obviously lol

Click to expand...

I donut know. Maybe? You'll want both and up and a down because you will find yourself under at some point too.