Reddit mentions of Water Quality Tester, Accurate and Reliable, HoneForest TDS Meter, EC Meter & Temperature Meter 3 in 1, 0-9990ppm, Ideal Water Test Meter for Drinking Water, Aquariums, etc.

There's a lot of useful info about growing in coco at Coco for Cannabis. He's all-in on using timers, automatic irrigation, and drain-to-waste with lots of runoff 100% of the time. It works really well, but it can be a bit tricky to get dialed in, and dealing with runoff can be a pain (especially if you care about disposing of it in an environmentally responsible way). I'd take his "you need to always water to 20% runoff" advice with a grain of salt; just try to water often enough that salts don't build up too much, and maybe err on the side of feeding with lower EC. Last grow I used automatic irrigation, but aimed for just barely having any runoff, and then hand-watered extra to get runoff once a week, when I felt like dealing with it. Definitely note his advice about
preparing and re-using coco, though. One of the best parts about coco is that you should be able to reuse it for a while.

There are other approaches, such as hempy buckets or bottom-feeding that may be simpler, particularly if you're doing a really small personal grow like I am. There's also an approach that combines them, with zero runoff. I haven't tried that one yet, but plant to try my next full size (not 1L SOG) run that way.

For nutrients, I don't know if it's available where you are, but I've been using Dyna-Gro: Foliage-Pro in veg, Bloom in flower. The only other thing I'd add is Pro-Tekt, a silica supplement that also works well as a pH Up. They're pretty inexpensive, simple to use, buffer pH nicely, great all-in-one option. People have also recommended MaxiBloom and Mega-Crop as other simple all-in-one fertilizers (both powdered). I can't personally speak to those, but worth looking into.

I use this EC/ppm meter and these pH test drops. I haven't tried using a pH meter, because the periodic calibration sounds like more trouble than it's worth. The EC meter and the test drops have worked fine for me, and in coco you'll probably only need to check pH of nutrient mixes, then compare EC going in (feed) and coming out (runoff). For that, the drops and that EC meter work great. (That EC meter probably isn't anything special, most cheap ones are probably fine.)

People will probably also recommend Grow Weed Easy, but some of their info about coco (particularly watering recommendations) is pretty dodgy. If you haven't done a full grow before, they have helpful info about harvesting and curing, though.

Strain recommendations will depend on a ton on personal taste, but I particularly like Mephisto's Fugue State. :) Good luck!

It look like you are doing great! Sometimes hiccups in the process will elongate things but you will learn and, in most cases, do so without too much detriment to your final harvest.

A bit of advice, if I may. Assuming you arent already doing so, grab an inexpensive TDS meter and start measuring/recording the EC of your inflow and outflow fertigation solution every time you feed. Once you start keeping track of these metrics you can stop guessing about whether you are under/overfeeding your gals. Unlike pH meters, TDS meters are not comprised of complex or terribly sensitive components, so spending a lot on a high dollar product is not necessary.

There are general guidelines about ppm ranges for both autos and photoperiods based on where they are in their lifecycle. As long as you keep within those ranges, it's rare to run into nutrient issues.

I also like to read GrowDiaries for the strains I'm growing to see how other folks fared with the same genetics and what pitfalls they ran into in their process.

Good luck with your garden, friend!

I got this one off amazon. Haven't really done extensive calibrating but it reads low in spring water and high in my tank water so...it seems good enough to give a ballpark reading.

Cheap PPM Meter

I’ve got one of these. They’re cheap but seem to be accurate and simple to use. I really like it. If you want a recommendation for a modestly priced but awesome Ph meter I can link to one too.

It’s likely the stress of transitioning that’s causing it. If you want a good way to jump start your flowering, put the plants in complete darkness for 24 hours, then put them under the 12/12 light schedule.

I fucked up on my current grow by accidentally doing that. I had an issue out in my grow shed so I had to move the plants to my garage. It wasn’t supposed to be more than a couple hours. Turned into a full day in the garage. The indica plant went straight into flowering. So now here I am.

Your best bet is to buy water testing strips off Amazon and test your water. Then adjust based on that. Don't just assume your Brita is doing enough. When you spend that much on an espresso machine ensure the water is good.

Test Strips

Water Quality Tester

Anti Scale Pouch

Edit: Formating

EC is Electrical conductivity. It measures the quantity of dissolved stuff, mostly salts, in the water and is a measurement of the strength of the nutrient solution. If you water with too high an EC you get nute burn. It's not actually nute "burn" but a result of the plant not being able to uptake water through osmosis.


Cannabis roots consume a lot of oxygen which they can not do if the soil is saturated. The soil MUST be allowed to become quite dry between watering so the roots can uptake oxygen.

GL!

Edit: This is the meter I use.

It's one of the things a lot of growers don't bother with but I consider it a "must have" meter. As important as pH.

The TDS of the RO (Bought from LFS) is 10 ppm. The Meter I use is: TDS Meter

I was looking at these online EC Meter at Amazon

Will eventually get one but trying to limit the gear for the first couple of runs. With gardening I have been going slowly to spread out the joy of learning and experimentation !

Probably chlorine, you can also get one of these to check for ppm Water Quality Tester, https://www.amazon.com/dp/B073713G5F/ref=cm_sw_r_cp_apa_i_5P4xCbVFMJWFQ

I didn't realize you'd already ordered the items in your list. That pH pen should work OK, but you'll need to calibrate it every couple of weeks. THIS kit has 4.0 and 7.0 calibration solutions and the storage solution. You definitely need those items to keep the pH pen operational (same goes for ANY pH meter). And you still need a tds/ppm meter... THIS cheap one should do.

I'm using one of these:

https://www.amazon.com/gp/product/B073713G5F/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

It is cheaply made, but the EC value it gives matched the lab work I had one on my tap water within a few percent.

How do you like that Apera meter?