Flushing in the middle of flowering?

[ReeferROb]

is it necessary to flush during flowering?? I am at 4 weeks flowering right now and they are doing awesome! They look great besides a little yellow between the veins on the big fan leaves. It couldnt hurt could it?

thanks
RR

 

[RooRman]

Using chemical fertilizers can cause waste salt to build up in the soil. Organic ferts. do not produce as much of this salt buildup. Gauge how often you must flush by the method you are using. I would say every 4 weeks is about right when using chemical ferts. and flushing twice for the entire grow (once when going veg.-flower, once before harvest) should be adequate when using organics.