I got a digital pH meter. Here's the Amazon link to it.
if you don't want to pay that much for blue lab pen, get this one.
comes with case and calibration solution ph 7 and ph 4.
$45 https://www.amazon.com/dp/B01ENFOHN8?ref=ppx_pop_mob_ap_share
Get a proper meter. Don't get a cheap one. This is as cheap as I would go. https://www.amazon.com/gp/product/B082DZBJFB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
This one is better https://www.amazon.com/gp/product/B01ENFOHN8/ref=ox_sc_saved_title_8?smid=ATVPDKIKX0DER&psc=1
Get a good pH meter. This one is the one Ive seen recommended a bunch so I bought it (and the storage solution). After having used crap pH meters in aquariums for years, this was a much needed upgrade and makes life so much easier.
https://www.amazon.com/dp/B01ENFOHN8?ref=ppx_yo2ov_dt_b_product_details&th=1
This because when you grow cannabis, ferns, cacti, succulents, philodendron, hoyas, etc. etc. etc. your water needs to be buffered spot on.
My only advice after my first 5 days is to purge with ahh-some when you first set up the tub for sure, and also that this tub sits on the larger end of what the frog@ease cartridge seems to be able to handle. Even at a setting of 4 it's having a hard time keeping to .5ppm free chlorine. I will report back after more experience. This tub is getting heavy use with 2 person morning sessions of 30mins each or more, 3 person afternoon sessions of 30mins, and 5 person evening sessions of 30 minutes.
One recommendation that I have is to get a taylor k2006c test kit, as it's vastly more accurate than the strips, however with ANY test kits you get, you will need to ignore combined chlorine on the tests when using @ease. This thread at TFP explains (a lot) more.
I highly recommend reading this: https://www.troublefreepool.com/threads/jumping-back-in-bullfrog-a5l-with-smartchlor.186281/
Test Kit I am using (i got mine cheaper @ebay but amazon has the reviews):
Amazon:https://www.amazon.com/dp/B0002IXIJ0
Ebay: https://www.ebay.com/itm/402335621331
Also a stirrer is super helpful with titration kits like the Taylor kit: https://www.amazon.com/Magnetic-Stirrer-Speedstir-Start-Up-Batteries/dp/B004BGPC5W
I find ALL color based pH tests hard to read, and I find the cheap 12 dollar ph sticks on Amazon don't last long when testing things like Chlorinated water, and they don't like getting wet. This pH tester is an Amazing consumer grade electronic option that I am loving for Saltwater fish, the hot tub, and my plant watering testing:
Apera pH meter: https://www.amazon.com/dp/B01ENFOHN8
I also ordered a Cascadia jet pack for the waterfall since mine didn't come with one.
Good luck!
Do you mean 0.5-1.5? That would be pretty bad. But if it's 0.15-0.5 that's not too bad.
Here is a really good pH meter but it's expensive: https://www.amazon.com/dp/B01ENFOHN8