Deficiency

[Lil Dab]

I did that in the beginning. But it would mess with my res to much. I had to use a shit load of ph down so i thought i only spray it.
Also i notized the silica not dissolving properly. At least it seemed so.

The silica needs to be added first and let sit for least half hour over night is best. Otherwise it binds with the calcium locks it all up and falls out of solution silica is a finicky

 

[hobby_farmer]

So i changed the Res with a new water that has less Calmag in it. I also reduced the Grow part a tiny bit so that i end up with an EC of 1,3mS.
Now my other plant is starting to show the same Symptoms(Brownish spots) beginning at the lower Leafs. And the "problem plant" isn't showing any sings of improvement...

A thing i noticed is that the EC is now constantly rising in the Res. Went up nearly 0,08mS in the last 12 hours.
Before the Res change it was pretty stable, or maybe even falling at a very slow rate.
What could that mean?

 

[BII]

Some contrary opinions:

Depending on your base nutrient product, you may not need to add cal-mag to RO water to "buffer" it. The posted nutrient regimen does not mention adding Ca and/or Mg. The nutes should have enough metal ions/salts, including Ca and Mg, to buffer the water and for your plants. And if not, consider switching nutes (such as I use MegCrop 2-part and at most add cal-mag 1-2 times during a grow, and usually do that foliarly).

For foliar feeding consider using Transport from Optic Foliar. This allows more effective and convenient feeding, on the top of leaves not undersides; and lights on/off doesn't matter.

 

[hobby_farmer]

Okay i read the ingredient's and here are the most important values:

• NPK Ratio: 12-6-16
• Calcium (Ca): 6%
• Magnesium (Mg): 3.3%

With a dosage of about 1,3g/L

a. Calcium (Ca) Calculation​

1. Percentage to Grams:
   • 6% Ca in 1.3 grams of nutrient:
   0.06×1.3 g=0.078
2. Grams to Milligrams:
   0.078 g×1000=78 mg

b. Magnesium (Mg) Calculation​

1. Percentage to Grams:
   • 3.3% Mg in 1.3 grams of nutrient:
   0.033×1.3 g=0.0429
2. Grams to Milligrams:
   0.0429 g×1000=42.9 mg

If i remember right a Cal/Mg of about 80/30 was good in this stage so maybe your right. My nutrients should have enough

 

[BII]

I wouldn't add Ca/Mg unless I knew the plant(s) needed it, such as the base nutes manufacturer or consensus of nutrient users recommends it or there were signs of a deficiency, and then I'd favor foliar feeding. Or I'd switch to more modern base nutrients that will both "buffer" near zero ppm/EC water and provide the plants with proper Ca and Mg levels.

 

[hobby_farmer]

So here's an Update on my Plants. It looks like my Nutrients had enough Cal/Mg even for RO water.
Changing the Res and putting the Calmag out of reach made my plants happy.
But now i have a different Problem. The Leafs are dropping pretty bad on the Imperium X.
EC is now 1.4 with the preflower nutrient mix. PH still around 6.
I read a lot about dropping Leafs in DWC but it doesn't really make any sense. Roots look perfectly healty. Water temp is constantly 19-20°C and i have 2 Air stones for each plant. Probably somewhat about 13-18 liters per minute of air for each plant.

Here are her Roots:

And this is here Sister(Wham Boom).

Compared to the other plant she's a Beauty but i think she's also starting to drop....

 

[hobby_farmer]

I thought i give this thread a little update.

They have recovered. Its been a rough ride.
But there were a few key points that i think made a big difference.

The first thing i needed to get under control was the dropping Leafs on the right plant.
As soon as i started using Liquid Silica instead of the weird powdered stuff she startet to recover slowly.
I used the exact same mixing order.
First Silica, then mixing and waiting. And then everything else from Calmag->Nuts->Additives.

Anyways, once the plant was somewhat stable, I focused on fine-tuning my nutrient mix. I noticed that both the EC and pH were climbing, so I ran some calculations to optimize the feed.

Initially, my pre-flower feeding schedule had an NPK ratio of 1.5 : 1.92 : 2.58, which wasn’t ideal. Using Excel and some extra parts from T.A., I adjusted it to 0.94 : 2.44 : 2.01.This change even reduced the total PPM.

Old
NPK (144/80,22/205,84)
Cal/Mg/S (104/82,4/176)

New nuts:
NPK (96/108,56/170,15)
Cal/Mg/S (71/46,5/87,6)
Note: These values reflect the parts per million, with P₂O₅ and K₂O already converted to their soluble forms (using factors 4.36 and 8.3).

I dont know why Terra Aquatica has such a weird ratio for preflower, the ratios for the other phases are way more optimal.
Here are my Ph and EC values. The big line in the Middle marks the Change from the Old mix to my special mix. Small arrow down means ph-. The PH is now more where i want it to be and more stable. An the EC is falling.

Here are my two girls now.