Alright, so I've been watering my collections with the fert formula that has been proposed. The tap water has been treated with dechlorinator and this is the result (I'll give the documentation later today):
- The tap water's original pH was 7.10 (it shifted between 7.00 to 7.10)
- There are two phases of pH change in my water after the ferts were applied: at 0-30 minutes, it was pH 6.26; when I left them overnight, it became 6.86
I've planned to use METALIK fert next week so this session didn't use said fert, since at the time of fertilizing, there's no update on how much METALIK ferts I need to apply.
Now onto your latest post:
Steve Johnson wrote: ↑Mon Sep 25, 2023 9:45 pm
Hi Adi,
I just wanted to give you an update...
5 ml = 1 metric teaspoon, so when you add Metalik to your 50-liter buckets of watering solution, you can "shade" a little under 1 tsp. Please don't forget to give me the pH number of your tap water after you add the fertilizers for dilution.
While we're here, I'd like to bring up a matter of general growing practice in case you're not already aware of it. With desert cacti under pot cultivation, the roots should be allowed to go from wet to completely dry top-to-bottom before they're watered again. Some growers are able to feel the weight of their pots by hand so they know if their cacti should be watered or not. Can you feel the difference between wet and completely bone-dry mix in your pots? If you can, let this be your guide for a good watering schedule. You may already be doing it. If not, hand-weighing pots is something you'll have to develop a feel for, but with a little bit of time and practice, you'll get the hang of it more quickly than you might think. Given the size of your collection, weighing every single pot won't be practical, so weigh a few different pot sizes that represent what you have in the collection.
Weighing pots before and after watering, in my collections, is only applicable to small ones - less than 15 cm in diameter - but since I potted all of them, I get to feel how light/heavy they are when they're dry or wet. Also, I got to visually judge any cacti that needs water, and often I get a small piece of tree branch and gently poke the cacti; if it's still firm, I can go easy with watering, if it yields, I'll water them straight up. For spineless cacti, I'll just gently squeeze them just to see if they're still firm enough or yield to pressure (this is how I also check any caudiciforms when they need water or not). Though, if you insist on weighing the pots, I've got it covered; I already got 'that feeling'. Light pots, dry. Heavy pots (when I grunt a bit while lifting them), wet.
To give you some context, I once do this experiment some time before I know this website to determine how fast my mix - scoria, pumice, and humus - dries out. The pots were about 10 - 20 cm. I let them dry out for a week and the smaller pots dried out about three to four days, and the bigger ones dried out about five or six days (though this result may vary depending on how much sunlight and wind enter my garden, as well as the weather and time of the year).
Also I use plastic pots, with various kinds of plastic materials. Shall I bring that to the conversation as well?
](./images/smilies/eusa_wall.gif "Brick wall"){kind=small}
The left one is potassium nitrate, with 15% nitrate and 15% potassium oxide. The right one is the calcium nitrate, with 14.4% nitrate and 18.6% calcium from 26% calcium oxide. Both are granular in form.
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