Yes, SLG pretty much duplicated what I had at the time. I did a 4, 6 and 8 site DIY fallponics based on Gary at PA hydro's designs.
@Observer the fallponics is a version of RDWC where the supply is higher than the water level creating a waterfall / splashing for more O2. It does not remove the need for bubbling tho.
OK SkinnyP, if this were me I would want to make this a quiet as possible since it is in your bedroom. Being in an apartment, I think you said 2nd floor, another major concern is leaking. Make sure your air pump is higher than any water in the system to prevent siphoning. The PA system uses quality bulkheads and square plant sites, so overall that will not be a big factor in leaks. 9 times out of 10, it is a mistake by the grower that causes flooding.
If the splashing is too loud, you can put a 90 inside the plant sites to get the supply under the water line. In my testing with DO meter, the fall in the fallponics does not really do much to overall O2 levels by itself. If you have proper bubbling, that is what you really need.
In terms of environment, what you are looking for is a proper VPD for the stage of the plant. VPD is nothing more than a way to design for the proper flow of water and nutes from the roots to the atmosphere via leaves. It takes RH and Temp and makes sure the ratio is right.
View attachment 76330
Given your situation, you will pretty much be controlling both RH and Temp via the exhaust blower. This will be a compromise you will have to work with the lung room (your bedroom) temp and RH mixing with the growspace and adjust things for the best you can do. You probably will not need any heat because the lights supply that, but RH can be a real issue. Especially on fast growing plants in hydro. Chances are when the plants get bigger, like towards the end of veg your RH will be your limiting factor, and your blower will be working to get rid of water in the air more than adjusting temp.
Solve For: Temp RH VPD Temp (F) Temp (C) RH (%) VPD Air (kPa) Leaf Offset (F) Leaf Offset (C) VPD Leaf (kPa)
pulsegrow.com
That calculator will help you to see what needs to be happening for best results.
RH will often peak once lights go out. Temps drop, making RH surge. This, if not handled properly, can cause mold. Especially in flower.
Because you are in a northern cold/dry climate, as you push the warm moist air out of the tent and out of your apartment, new air from outside will find it's way into your house via every crack in doors, windows, etc. If it is cold out, this means your furnace will kick on, making your apartment air even more dry. This can be a big help in controlling RH in the tent.
My biggest suggestion for you would be to put up the tent, and start 1 plant in soil or coco just to get an idea of how everything works and measures out in your environment. Once we have some real world measurements we can tune the setup to be able to properly handle the loads from a fast growing RDWC system. The plants will grow faster / bigger in RDWC, but that comes at the cost of need for additional environmental controls. For example, before I added a chiller, I would spend that money on a dehumidifier most likely.
