CO2 is the building block of plants, the brick and mortar to your house, composing about 50% of your plants dessicated body. Your plant needs C02 to be broken down and turned into sugars via photosynthetic (lighty light) energy creation. Plants photosynthesize better when there's more light (cuz they got that whole thing going for them), and ergo absorb more C02 in the process to facilitate such energetic ideals. C02 is also directly affected by your karbonate hardness, which plays with your ph which turns your carbonate ions into bicarbonate and C02 ions which lowers your ph which funks your shuff up mate! All plants need C02 to in essence exist, all dao like and stuff.
You sound like you got a bad case of the high-light-requiring-plants-that need-to-grow-really-often-and-fast-or-die. Sounds like you're using a liquid source of carbon. Liquid sources just don't cut it always bubba! Could be your light system just isn't strong enough either for what chew got. So, what chew got?
Holes in the leaves could just as easily be a macro nutrient deficiency and as far as I'm aware, your hygro's leaves won't repair after damage. If you mean more leave are getting blotchy, I still like my first answer. But it's your tank and I'm just gandering a guess. And that's all I got?