how to change/flush my hydroponic system

[ELsNjAys]

Allright, I have the basic layout and room selected. About a 4.5x4.5 walkin closet, and definitely set at this point on using rockwool slabs and cubes. My set up as it stands consists of four kitty litter boxes that each will have rockwool slabs in them and then grow cubes on top. These will sit in a resevoir of water/nutrients. I have read that every so often, 2 weeks about, you should flush the water out to prevent buildup of certain compounds. My question is how do I accomplish this once the plants start getting bigger? Would this exact system put into a larger resevoir, and supplemented with a pump and hoses be an improvement, or more of a hassle? (i.e. the large resevoir will be the only thing that has water sitting in it, the kitty litter boxes would be slightly elevated and water will be pumped to their tops and allowed to trickle down)

[linedrivr]

get yourself a submersible 200+gph pump ($15 or so), attach a 3' x 1/2" or 3/4" hose to it and drop it in your reservoir. when you are ready to change out your reservoir, get a 5 gal bucket, place the loose end of your hose in the empty bucket and power on your pump. once the reservoir is empty, pour the bucket contents down the toilet.

or

if you have a drain (toilet, shower, sink) somewhere reasonably close, run you a hose long enough to reach the drain from the pump in the reservoir, turn it on and drain away.

regards,
linedrivr