Light? Wrong.

Do not start to flower them yet. That problem is a SEVERE pH imbalance or toxic salt buildup- either way, the treatment is the same.

Make a solution of plain tap water, you may add Clearex if you like, or a little Soil Syrup, with the pH adjusted to 6.8.

Flush your pots THROROUGHLY with this. You should use water equivalent to 3 times the volume of the pot.

Now make up a watering solution of a complete fert with micronutrients at about half the strength recommended on the bottle. Adjust to pH 6.8 and water with this.

If that's peat soil, repot into a slightly larger container with a nice light soil that is NOT peat- the compost mix in the link in my sig is ideal for nursing sick plants back to health.