Oh man you got to be kidding me, why does everyone suggest using H202 at the slightest hint of trouble. I have heard about people having problems with MG soil but you know what, let them grow and I'm sure they will be just fine. Most problems with plants tend to go away on their own! Every time I have seen someone use H202 on these forums it has made the situation worse! Using H202 on a sick, weak, or young plant will probably kill it. Just water them once a week with water and most of the time things work themselves out on their own. In the future if you're growing with soil this is what I do and have good results. Get yourself a bag of LIGHT WARRIOR. It is basically seed starter which is a very lite Peat based grow mix and is the perfect stuff for growing seeds, I think its a little too light and I mix in a little Happy Frog with it to thicken it up and make it hold a little more water but its not needed. For soil grows I would not use MG for anything ever. Fox Farm soil is a little harder to find, you have to get it at a grow store, but its perfect for growing pot. I prefer the FF HAPPY FROG because it has Dolomite Lime and Humic Acid and it is not as hot nitrogen wise as Fox Farm Ocean Forrest. So it is good for when you transplant or for younger plants. MG and pot just don't get along for whatever reason. Ocean Forrest is good soil as well and I have done grows where I used a 3 gallon smart pot of Ocean Forrest and added no fertilizers whatsoever and grew some of the dankest train wreck I have ever seen. It was even better than the wreck they had at the dispensary for sale. I whipped out a Acorn sized bud, with huge Calyxes and gifted it to one of the guys at the dispensary and they were even impressed. Whatever you do, please don't hit them with H202. That can only make things worse, and SensiZym and Hygrozyme do the exact same thing as hydrogen peroxide without hurting the plant. H202 has a place in a grow, don't get me wrong I use it if I need to clean out the hydro systems or pots AFTER a grow, but why anyone would use H202 on a living plant as anything but a last last resort is beyond me when there are tons of products out there that are better and less harsh on the plant. Better yet, just giving them water and they will probably heal themselves. I've had plants that got sick, and every single leaf was damaged because I used neem during lights on and burnt the plants. You know what, the plant shed all the damaged leaves slowly, and grew new ones. That plant went on to be some of the dankest Lemon Diesel I have ever grown and I nearly killed it. Give it time, leave it alone, and the plant WILL heal itself. Also, If you're careful you can dig the plant up and transplant it to a pot with better soil. I would try that before using H202 because that WILL fuck your plant up more.
Sigh.....