Leaf tips turning brown

This is the result of over feeding with "Tiger Bloom"......... what is showing now in the leaves is a direct reflection of what occurred in the soil 2 weeks ago. Cal/mag is only needed every 10 days or so in soil and since you stopped all togetger with the Tiger Bloom for 2 weeks already, you should be safe to resume feeding with it at half the strength of what you were giving previously. Remember too, in good soil it is a schedule of plain water/plain water/feed/plain water/plain water/feed.........so that your plants are only being fed every 10-14 days. Soil "holds onto" nutrients better than other substrates, so the plants need to use what is already there, before new nutrients are added, otherwise burning can occur.