Dilution effect: when more flower lowers the concentration

If a plant forms less flower, its THC value in the lab can rise. THC is the main intoxicating compound. The plant has not made more of it. The THC it has just sits in less mass. This is called the dilution effect. The same amount of sugar tastes sweeter in half a glass of water than in a full one.

How do you spot it in your own harvest?

Potency goes up, harvest weight goes down. What counts is the amount of compound per plant. 100 g of flower at 20 % THC hold 20 g of THC. 70 g of flower at 25 % THC hold only 17.5 g. Despite the better lab value, the harvest holds an eighth less THC.

  • Weigh the dried flower of each plant.
  • Multiply weight by the lab value.
  • Compare only that amount, never the percentage alone.

Which measures bring it about?

Often whatever slows growth. With phosphorus deficiency potency rose by up to a quarter. Yield and the amount of compound per plant fell, though. Sometimes only the harvest shrinks, and the lab value stays the same. Without nitrogen the flower shrank to a good quarter, and potency stayed the same.

  • After a deficiency, drought or flushing, check harvest weight first.
  • The same lab value with less flower means less active compound.

Is every higher concentration a dilution?

No. If potency and amount rise together, the plant really made more. A cultivar left to wilt before harvest had about an eighth more potency. The amount of compound per area rose by over 40 %.

  • With any report of more THC, look for the harvest weight.
  • If the weight is missing, do not adopt the claim.

How do you compare fairly?

Same plants, same treatment, only one difference. Potency also varies between top and lower flowers.

  1. Split cuttings, rooted clones of one mother plant, into two groups of equal size.
  2. Only one group gets the treatment.
  3. Harvest both on the same day, dry them the same way and weigh each plant.
  4. Always take the lab sample from the same spot, such as the top flower.
  5. Compare the amount per plant.

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