Building Hydroponic system - I THINK?? Part 2

Well I thought I would share my progress with my hydroponic tables. The tables work great. I have had a few bugs one is the fact that the water evaporates at a alarming rate. I usually have to refill the trough around 1 a day. I usually over flow the trough so the their is less salt build up. Another problem I have noticed is to much fertilizer can effect the whole table fairly bad and measuring the amount in the table can be more a hit or miss. I have sence kept the doses on a fairly low level. Anyone have any suggestions on a quick and easy way to test the water so I don't get any root burn?

Other than the two problems above this has been some of the best results I have had growing these plants.

I use the Truncheon TDS / EC Meter and it had preformed well for me. Your system looks great but with the open tank and open tables you will have a problem with evaporation and algae. I added a cattle trough fill valve to my system and it keeps the tank topped off all the time. You can get the plastic valves fill valve for about $12 but the Trucheon is going to be about $130.
Oldude

Thanks I was wondering if I was going to have to make a valve to fill these up or if their was something already on the market that would work.

You can find them at any local cattle feed store . Here is a link http://www.jefferslivestock.com/ssc/products.asp?CID=2&area=swine&dept_id=326

Hey! I have a pH test kit here at the store for $7.95 in downtown Louisville. I am only open on the weekends though. You fill a little tiny container with water and put a drop into it to test the pH. Alot cheaper than a meter...I have those too. Some meters measure EC salt content...that helps. Can you cover your tanks that hold the water? That might help too on losing water. They look great! You might want to totally drain out all of the water at least every 2-3 weeks and start fresh. They say if you top off your tank you should add 20% fertilizer too. It might have been 30%..I forget....
take it easy!!!
Your tables look awesome!

Thanks if I can ever get down I will be sure to stop in. It seems like I work 8 days a week here. If your ever in I would love for you to take a look at my system and hopefully you can give me some suggestions with a few problems I have been having.