Brown-orange leafs, dry - too much fertilized soil?

[Elehem]

Hello, im currently on my first grow with 2x Royal Dwarfs. I used 1/3 Compo Sana Seedling Soil on the upper half and 2/3 Compo Sana Quality Flower Soil on the lower parts.
Im using tap water to water the two plants every 2-3 days, till a little bit of water drops from the bottom of the bucket.

Looks like fertilizer burn, doesnt it?

http://imgur.com/a/bN5zk

Thanks in advance.

 

[MostlyMe]

If you are completely soaking the soil every 2-3 days, you're overwatering to the extreme. I often don't water my seedlings for 1-2 weeks after starting them in mildly moist soil. This of course depends on ambient conditions and pot size.

You might want to consider carefully digging out your plant and repot it in mildly moistened soil. If you don't fancy that, you have to stop watering and wait until the soil dries out.

 

[Elehem]

Thanks for the reply.

I will stop watering for the next couple days and watch how the plants develop. Watered the last time 2 days ago.

If there are still leaves that get tip burns, i will consider repotting.

How long should i water them only sparely?

 

[Hans-von-Dampf]

Actually ... until harvest

Marijuana is neither a tropical plant nor a vegetable
It doesn't need excessive amounts of water. it even developed a mechanism to prevent losing too much moisture: it produces a resin that covers the buds ... which is the reason people grow, harvest & smoke it.

Water when you soil dries out. That means: before it turns into a crackling desert, but not until it's actually necessary. That takes two things:

an eye on how the plant behaves (when it starts drooping, you're a little too late but still in the clear: slowly add water until you got some run off) and ...

Very light pots (I use simple plastic pots). Those will help you determine when your soil is dry enough to water the plants again. Just lift them, feel "how dry they weigh" and water if necessary.

Just make sure they have a higher RH in veg and the lowest RH possible in bloom (watering raises RH in tents so watering too often will affect not only your roots, but can cause bud rot and everything else that comes along with too high humidity)

But overall ... weed doesn't need all that much water. It is a weed after all ... just make sure it doesn't have to be thirsty

 

[Elehem]

thanks for the detailed reply.

i didnt water since 5 days now and it looks like it stopped.
i wouldve drowned them .

 

[Elehem]

Ok im now getting some brown spots inside the leaf on some older leaves.

Which fertilizer should i use? Canna Terra Vega or Biowizz?

 

[Elehem]

As i cannot edit my post somehow, some additional information:

- Looks like calcium deficiency.
- I think i will use BioBizz with 1ml per 1l water to not over fertilize the already fertilized soil.

 

[MostlyMe]

Brown spot on lower leaves is more likely a magnesium problem. Could be pH related or a lock-out if your water is very hard, but in this case a deficiency is most likely. Spraying with epsom salt or another supplement is safest, perhaps a pinch with a single watering is also in order.

 

[Elehem]

The picture above is from calcium deficiency. But yeah i think my ph is too low because of the pretty intense fertilized soil and its locking my nutrients.

I will buy some chalk 95 % CaCO3 (Calciumcarbonat) tomorrow to rise the ph to 6.5 and some ph soil tester.

 

[Elehem]

I couldnt wait. Made a ph soil test and it resulted in a 5.2 - 5.7 ph (color based approximation).
I bought and added some chalk with calcium (88%) and magnesium(5%). Will do another ph test in a couple of days and will see how it turns out.

 

[Mikell]

How are you testing soil pH?

 

[MostlyMe]

Adding some chalk/lime is a good idea, it takes care of the pH problem (if that is the case, soil pH measurement is tricky) and the deficiency at the same time. I'd prefer something with a little more Mg though.

Most manufacturers don't have Mg and Ca in their nutes, because they count on the soil and tap water to provide them. That's why beginning growers often encounter problems, if they happen to grow a relatively Ca/Mg hungry strain.

 

[Elehem]

How are you testing soil pH?

like this: http://bloomsandfood.com/tag/how-to-do-a-soil-ph-test/

Adding some chalk/lime is a good idea, it takes care of the pH problem (if that is the case, soil pH measurement is tricky) and the deficiency at the same time. I'd prefer something with a little more Mg though.

Most manufacturers don't have Mg and Ca in their nutes, because they count on the soil and tap water to provide them. That's why beginning growers often encounter problems, if they happen to grow a relatively Ca/Mg hungry strain.

I was happy to even find chalk with any Mg. I will try to stabilize my pH so the plant will be able to absorb the Mg and Ca of the soil again and i also bought CompoSana Complete, which has a high amount of Ca and Mg and will use this later if its still hungry for more Ca and Mg.