Water ph question

I'm going to be beginning my first dwc hydro grow and I wanted to do a test run with no plant to get an idea of how to get the right ph and ppm levels. I use distilled water only and there is plenty of bubbles coming from my air stones. My expanded clay was washed thoroughly and soaked in 5.0 pH water over night....

I do not have a ph pen but I plan on investing in one very soon. For now I am using a combination of drops/strips.

i phed my water with the drops to around 5.5 or orange/yellow on General hydroponics kit. 3 days later I checked my ph again and it was blue and around 8-9 ph.....

does the ph of water change over time or what would cause it to change that much in 3 days? My ppm dropped about 30 over the few days but I'm guessing it was due to evaporation.

Any help/tips would be appreciated. Thanks

Tho I'm not a DWC grower, I do do flood to drain, and my ph always ends up higher after a few feedings, to me that's normal, I just re-adjust before next feeding, not sure but think you should strive for a ph of 5.8.

You can get away with just drops at first but a ph pen is a necessity. You'll need one when you fill your DWC with plants. More importantly you'll need a TDS pen to check ppms and mix up nutrients. Get some practice checking ph for sure but you are not going to see much action until you have plants to affect the water & nutrients in the reservior. Basically if your ph is low (less than 5.5) you've probably got an issue with bacteria in your reservior...if it's high(over 6.5) your plants are using up the nutrients in the reservior. I found this out the hard way.
A glass of water is around 7.0 which shows green- add some down & try to get it to 6.0 but it won't stay there long unless there are ph buffers present- the nutrients contain buffers to regulate ph- so play around & learn but without any plants in the bucket you won't see much happening

What are some good nutes that have ph buffers? I'm currently using the fox farm trio but I believe they do not have ph buffers. Thanks

Yes they do those will work just fine in your DWC. If you add the nutrients to the water as the recipe says your water should be 6.0 but that will change when there are roots from live plants hanging down there. However using the nutrients as directed on the label or recipe card you will burn them in a DWC grow. Start your seedlings with nothing but water for first 2-3 weeks then mix the nutrient to a weak 300-400 ppm for the next few weeks. When you are in full veg you should have around 500-600 ppms of nutrient in your res and then maybe go on up to 700 in late flower phase. Never use it full strength in DWC

The steps are thus: mix up your nutrients, add to the reservior, then check ph... Doing it any other way causes confusion & you'll be chasing your readings. I think it's easier to mix up the nutrients in a tub the same size as the res then just use a pump to transfer it in. One more tip- use a syringe to add ph up or down. I tried using a measuring spoon for this at first but always added too much & ended up adjusting the opposite way to compensate...ugh!

Oh and use the metric system- ml are easier to calculate than tsp & tblsps when mixing up nutes

Thanks for the info I appreciate it. I've been practicing with ppm and ph.... However I read in a few places that clones should start out around 100-200 ppm is this too much? Should I use no nutes, just calmag and RO WATER?

I just finished my first Dwc last week and had issues with pH stability as well. In for some great info.

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Without nutes in the water the pH will never stay where you want it.

That makes since then why my ph went way off after about 4-5 days. Since there were minimal nutrients in the water I the buffers were not strong enough to maintain a stable ph. I'll keep my eyes on ph for the first few weeks checking daily. Thanks for the help

Starting out you will need to adjust ph all the time due to the lack of nutrient/Ph buffers but once the roots are hanging down in the water you can slowly add your 1/4 strength fox farm nutrients and yes don't forget a small amount of cal-mag. Once the plants get a few nodes you can up the ppms & then your ph should level off in range (5.5-6.5) & will not be as much of an issue anymore. Using hygrozyme also helps regulate the ph by introducing beneficial bacteria that eats the baddies in your res- only staves it off actually. Regular res changes are also essential in DWC to avoid the dreaded root rot- you'll know you have a problem with funk if your ph is always low- been through the ringer on this I can tell you