When it's dry, feed water only. A quantity sufficient for runoff equal to the container's size (i.e., 100% runoff). In more extreme cases, 300%. In less extreme cases, just 50% and perhaps mild nutes instead of water only.
A photo would help. But, over feeding is common (leading to salt buildup in early flower, acidic soil, nute lockout). Over feeding also causes brittle glossy leaves.
Which MG nutes are you feeding? You can mix them together to get less extreme NPK ratios. For example, if you switched abruptly to "Bloom Booster" (NPK ratio 1-2-1) that can cause the plant to deteriorate. If you were using "All Purpose" (3-1-2), you could mix those 30/70% (AP/BB) to get a relatively sane 1.2-1.5-1 for early and mid flower. Don't go 100% BB until late flower.
This is why you don't need to "upgrade" to boutique cannabis-specific nutrients. It's all about the NPK ratio and strength. You can get that with anything. You don't need to pay a cannabis-tax buying themed products. Just ordinary fertilizers will get you where you need to be.