yellowing new leaf tips

Looks like the beginning of burning due to feeding too much or too often, or both. The blue/green colour of some leaves can be a sign of too much nitrogen. In soil, a schedule of plain water/plain water/feed/plain water/plain water/feed works well, so that your plant is only being fed every 10-14 days. Soil "holds onto" nutrients more so than any other substrate and the plant needs to consume what is already in the soil before new nutrients are added, hence only feeding every 12 days or so. If this plant is an auto, half strength nutrients is usually plenty. Remember too, it is very easy to fix a slightly under fed plant, but very, very hard to rescue a badly burned and over fed plant. At this point, I would give just plain water, in normal amounts and at normal intervals, for the next 10 days, before resuming feeding with half strength nutrients. Watering to run off is also important, this helps prevent nutrient salts from building up to toxic levels. It is also the only way to know for sure that water has got right down to the bottom of the pot, which is where most of the roots will be going. No need to flush this plant with extreme amounts of water, this just kills most of the soil microbes, as well as releasing even more nitrogen from the soil, causing even more problems. Hope this helps, Organoman.