manure tea

ive just started to make a batch of tea from chicken and sheep manure was reading some where this is only really good in the veg stage as its to high in nitrogen for flowering is there any truth to this?
also if i use organic nutes does the plant still have to be flushed?

Without an accurate NPK analysis, we really can't say whether the mix is good or bad for anything. It is true that plants use mostly Nitrogen during veg and that the majority of plants use mostly Potassium during flowering. A high-N fertilizer would indeed be better for veg than flowering. Manures are usually acidic so check the pH and adjust if necessary.

This second question is debatable and you'll find many discussions about it in these forums. The short answer is no, it does not have to be flushed.