Yellow patches/dots in coco

[honeysoi]

Hi all,
Looking for some advice, unfortunately I needed to plant my germinated seeds and my store was out of my usual coco mix, so I settled on bricks from bunnings. I flushed it all well before use as advised. I am feeding my usual mix of calmag and canna coco AB. I did notice when they were small seedlings what looked like Ca deficiency so I've been daily foliar feeding with calmag. I didn't get a good photo of the damage but you can see it in the first photo. I chopped those 4 leaves off and now new spots are appearing. Any ideas? TIA.

 

[Pineboy212]

Check ya ph im thinking it’s low
Hope it helps

 

[bongsmoker421]

Hi all,
Looking for some advice, unfortunately I needed to plant my germinated seeds and my store was out of my usual coco mix, so I settled on bricks from bunnings. I flushed it all well before use as advised. I am feeding my usual mix of calmag and canna coco AB. I did notice when they were small seedlings what looked like Ca deficiency so I've been daily foliar feeding with calmag. I didn't get a good photo of the damage but you can see it in the first photo. I chopped those 4 leaves off and now new spots are appearing. Any ideas? TIA.

I don't chop off leaves until they're ready to die. Typically the plant is withdrawing nutrient from the affected leaves to feed the plant. When you cut those leaves off, it will find another leaf to get the nutrients from. So by keeping the affected leaf on the plant you're actually protecting the rest of the plant, which is why you see new spots appearing. As far as why, I'm not sure as I've never ran anything besides soil but have heard of coco being notorious for calmag deficiencies. But I agree with pineboy check the ph first before next steps. Idk what ideal range for coco is a think slightly more acidic than soil.

 

[honeysoi]

Appreciate the feedback. I will leave the leaves on for now. What's the best method the check the pH in coco? I've read the runoff pH should be ignored

 

[bongsmoker421]

Appreciate the feedback. I will leave the leaves on for now. What's the best method the check the pH in coco? I've read the runoff pH should be ignored

I use this. It's like 20 bucks. You can find it at most aquatic pet shop stores, or hydro store. If you've ever played with pH paper in middle school or high-school you'll have no problem. There are also affordable ph pens off Amazon. vivosun has them for like 16 bucks and comes paired with a ppm pen. I plan on purchasing a pen myself pretty soon.

 

[honeysoi]

I have a very good pH pen and have ph up down. Just unsure of best way to test the medium pH. I always pH nute water