Time release nutes in soil question?

I made the mistake of buying "Expert Gardener" soil at wal mart. says 9 months feed. plants are doing great. I just turned them to flower yesterday and want to know when to start adding nutrients. I am using Botanicare cns17 bloom and Ripe. Plants right now show no signs of deficiancy. when to nute is the question. the plants are about 30+ days veg. See my grow below for pics

Giving the plant some extra Potassium as soon as you switch to 12/12 helps it realize faster that it's flowering time. It can also prevent having a sudden K deficiency when the flowers start to appear. Extra K now, let soil dry, plain water, let soil dry, normal flowering fertilizer with N, P and K, dry, plain water, normal flowering ferts again, etc. Increase fertilizer strength as the plant gets bigger. Often the K content needs to increase faster than the others as buds get bigger. Having the time release ferts just means you should start the normal flowering ferts at low strength, but follow the same system.

thanks.. that was very helpful and a very reassuring