PH Changes in DWC daily, is this normal?

I have some concerns about my DWC setup. I have 5 single bucket units. When I first set them up I added the nutes to a PPM around 300 and balanced the PH to 5.8.

I'm using FoxFarms Big Grow Hydro and Big Bloom. Each system has 3 gallons of water and the roots are just starting to sit in the water. The water level is about an inch below the pots.

Here's my problem and it could be normal I'm not sure. After I PH balance to 5.8 the next morning all the readings are up. They will vary anywhere from 6 to 7. So I have to PH balance again. Should I be doing this daily?

I'm not changing the nutes because the PPM and water levels are remaining the same. It's been this way for about 3 days in a row now.

(Side Note) I'm not sure if this matters, but it looks like the Big Bloom nutrients are not all dissolved in the water. It looks as though there is some sediment at the bottom of the buckets. Seems to be it looks like the particles of Big Bloom but could be wrong.

If I stir the water the PH level will drop a little but not back to the original level.

Any thoughts? Sorry for such a long post but I wanted to make sure I provided as much info as possible.

are you mixing the water after you ph balance then testing? what kind of water are you useing? How much water is in the bucket?

Yes, I am mixing the water then PH balancing. However, I'm PH balancing each morning it seems like. It's almost as though it's reverting. I'm just using tap water from my home, out of the tap it has a PH of 8 and PPM of 200.

Each bucket contains 3 gallons of water.

my res was 3 gal and i had to adjust ph daily? is your growing medium rockwool?

That is totally normal as the reservoir is kinda small for you plant... I have about 25-30gal of water with 18 plants right now and i ph my reservoir sometime twice a day.

My tap water is around 200ppm and ph is 8 also. If your ph is fluctuating daily then your water supplier most likely puts pH adjusting chemiclas in the water. This was happening to me as well and so I use distilled water. Distilled water has a pH of around 7 and ppm of 0. yes thats right its 0 ppm. I get it at walmart for 70cents per gallon.

I recommend filtering your water and not using straight tap water. I only have 1 bucket which is a 3 galon and so its convient for me to run and get 5 gal of water per week.

Distilled rocks but also check out R.O. water and get rid of ur current water.

when u change small amounts of water, the ph will flucuate greatly, try changing like 20 gallons in stead of 5, youll see a diff