Lucas Formula and Water Farms with controller

Ok here I go... I have just started up my 2nd grow and on this round Im using the GH Waterfarms with controller set up in a 6 pack configuration. Ive read through the ASK LUCAS FORUM and cant get a straight answer on this question I have. I have a full time PH / PPM Monitor monitoring the controller... My top reservoir is checked daily by hand to ensure stable PH Readings and 2 weeks into my grow, I have not had any of the problems of wild PH fluctuations many users report.

My question is, do I just continously top off the top reservoir with full strenght Lucas Formula at the 0-8-16 per gallon ratios?

I do see that people show 2 different methods of topping off but the add back gets a bit confusing so Im hoping to find someone with this experience with this specific scenario. Any and all information anyone can provide is greatly appreciated.

Well the easy way is to just add plain unPH'd water back until you have refilled the original res amount. There is a formula for the add back that i dont really know but i think that about a 33% add back should work well in most cases.

Thanks for replying.... Well after a thorough search on this forum and others, I have found a few people with about 15 yrs combined experience using the Lucas Formula and the Waterfarms and they have all confirmed what I assumed.

You just need to top off the main reservoir with PH'd Full Strength Lucas Formula and monitor PPMS and PH... Adjust PPMS and PH inside the controller with RO water to maintain optimum growing conditions.


I guess I still find it so hard to believe I at one point had DWC buckets all individually maintained. Learn from it and move on. Dont let the bad comments on the wild PH swings on a 8 pack WaterFarm System scare you away. Im no pro, but by following the simple advice offered on here I was able to make things a hell of a lot easier on myself.

Hope this short thread is able to help someone in the future and offer a bit of piece of mind with a clear answer to a simple question.

so are you saying that your addback water will be 100% nute strength? i believe that this is wrong but i can't tell you why till i look it up. if i were you i would just experiment with adding different concentrations of nutes (starting around thirty percent strength). your situation, reservoir, and nutrients are unique and you are going to have to find your own way to balance the levels out. it seems to me that if you added full strength solution to the res then your ppms would rise too quickly and your pH would drop.

but i don't know everything (*correction: i don't know anything)

good luck and let me know how it goes. i'm just starting with the lucas formula now

You should have your nutrient reservoir set up to add RO or ugh tap water to maintain a steady nutrient volume level constantly. Using a float level system/ultra sound/bubble sensors etc. with relays activating a pump or whatever. Just keep the volume constant before worrying about any thing else. Then using your conductivity/ppm meter you add by pump(s )(i.e. small/dual head peristaltic etc), straight nutrient concentrates (equal amount of both parts <ie dual heads>) to get the desired EC/ppm. You should also have two reservoirs and seperate small pumps with pH up and pH down of your choice to raise or lower the pH as needed.

You will find that most pH problems (changes) occur during vegging due to accumalation of ammonium fertilizers. Even without ammonium nitrate fertilizer being part of the nutrient formulation other fertilizers add some nitrogen as ammonium (bummer). This typically especially during budding causes the need for daily upward adjustments to the pH (especially if the nitrogen as ammonium is above about 15% of the total nitrogen).

We are talking at least three pump and at least four top off reservoirs plus your water top off pumps/reservoirs etc and your regular nutrient reservoir. Or you can use solenoid valves and gravity feed. All automatic except keeping the topoff/balancing reservoirs full.

And that is all for just one nutrient reservoir. At least there is economy in size. As your grow area gets bigger you do not need to increase the size or numbers of anything in the nutrient system except the reservoir sizes.

Ba da, ba da, boom.