Ganjafiend420 said:

Hey,

Bottom feeding in fabric pots is wild, I love it.

Based on what you're describing and the images, this could be a potassium deficiency. The brown spots and yellowing are often linked to a lack of potassium, which is especially important in the flowering stage, you’re in week 3.5, so the plant is using a lot more potassium to support bud development.

While Cal-Mag is great for calcium and magnesium, it doesn’t address potassium. Since you're using Fox Farm's trio, I’d recommend adding a potassium boost like a bloom booster or something that contains Mono Potassium Phosphate (MKP). This will help with the nutrient imbalance and support your buds.

Just make sure not to overdo it with Cal-Mag, as it can sometimes interfere with nutrient uptake if over-applied. Keep an eye on the new growth, it should improve once you adjust the nutrients.

Good luck, and keep pushing through, you're doing great!

Click to expand...

1. Flush the soil with plain pH-balanced water (around 6.2-6.5 for soil) to remove excess salts.
2. Reduce Cal-Mag dosage to around 2-3 ml/gal next feeding.
3. Monitor runoff pH and EC to ensure nutrient absorption is balanced.

FULL LENGTH VERSION:​

1. Flush the Soil​

• Purpose: To remove any excess nutrients or salts that might be causing a lockout.
• How: Water the plant with pH-balanced water (6.2-6.5 pH) until you see runoff. This will help to leach out excess salts and nutrients. Make sure the runoff water is tested for pH and EC (electrical conductivity) to gauge how much buildup you might have.

2. Adjust the Cal-Mag​

• Current Situation: You're using 5ml/gal of Cal-Mag, which might be too high.
• Recommended Dosage: Reduce it to 2-3 ml/gal in your next feeding, depending on your water's mineral content. If you are using tap water that already contains calcium and magnesium, you may even consider cutting it down further or skipping it entirely.

3. Feeding Schedule After Flush​

• Week 4 Flowering: At this stage, your plants need a balance of nutrients for bud development. Here’s a recommended feeding breakdown using the Fox Farm trio:
  • Grow Big: 1-2 tsp/gal (for continued vegetative support, but reduce as you move into the later flower phase)
  • Tiger Bloom: 2-3 tsp/gal (for flowering support, focus on this more than Grow Big)
  • Big Bloom: 2-3 tbsp/gal (to enhance flower development and nutrient uptake)

4. Monitor pH and EC​

• After the flush, check the runoff pH and EC (Electrical Conductivity)to ensure the soil is not too acidic/alkaline and that you don’t have too much nutrient buildup.
  • pH: Aim for 6.2-6.5 (if growing in soil).
  • EC: Aim for 1.5-2.0 for flowering plants, but it varies depending on strain and medium.

5. Check Water Quality​

• If you are using tap water, check its pH and EC levels as well. High levels of calcium or magnesium might require you to adjust the amount of Cal-Mag you're adding.

6. Continue Monitoring​

• Keep an eye on the yellowing and the rust spots. If the problem improves after these adjustments, it may indicate an overabundance of certain nutrients.
• If symptoms worsen, consider further reducing nutrient strength or adjusting the pH of your feed.