Are you replacing the water to maintain the level in the reservoir at a constant 1/2 inch below the net pot bottom? If not your plants are REALLY stressing going through drought and flood periods every week! Really it is best to have a top off tank connected to a float valve in the reservoir. The water in your top off needs to be PHed, aerated and about 12% of the strength of your regular reservoir or about 200 PPMs.
Thanks for this advice, cause that is exactly what I have been doing. Once the water gets low about 2 inches in my buckets I mix fresh nutes and fill it back up to about 1/2 below net pot.