My 4-yr old son wanted to help me assemble Dosatron last week, so we managed to get the installation done "quickly". Actually, those CPVC connectors are much more expensive than I expected. PVC would probably be cheaper. But I had to get the shopping done while a 4-yr old was still helpful (not enough time to do comparison shopping). I think that it does make quite a bit of noise. I wouldn't call it too noisy unless I'm running it at a high flow rate. But it could be heard from the bedroom. But at the low flow rate (I'm using 0.5gpm head), it doesn't click too frequently. So it is ok for now. It is probably not so noisy in greenhouse where fans might be making lots of noise. Kelly, I was wong about the EC/TDS method. I think most of the cheap meters can't measure the EC/TDS of the stock solution. I mixed the stock so that it should be giving 30ppmN at the output with 1:100. So I'm comparing the EC from the Dosatron mixed water against the EC of the manually mixed water to confirm the accuracy. Or with the volumetric check, I'm going to see if I can use a digital balance to check the mixing ratio.