I'll be happy to help you understand ec (electrical conductivity) and the relationship to ppm in regards to the specific meter you are using. Some meters use a .5 conversion factor and others use a .7 conversion factor. Step 1 is to find out what conversion factor is associated with your meter (check the manual on hand or find a pdf file of such product literature online). If your ec is .8 it could never be 140 ppm at either conversion factor. A .8 ec on a .5 conversion meter (such as a hanna) will translate to 400 ppm. If you have a .7 conversion meter then a .8 ec will translate to 560 ppm. In my experience with dwc, an ec of 1.2-1.4 will be perfect for your tomatoes. 1150 is too high if the roots are constantly submersed in the nutrient solution.If you are dripping onto rock wool from a repeat cycle dosing system some may say higher nutes are ok, but in that case I would say throw your rock wool in the garbage and build a proper dwc using proper pond aeration principles and never look back. You will still use the same ratio of GH flora duo (aka Lucas formula or aka Lucas ratio) but less per gallon of water to achieve the 1.2-1.4 ec. That ratio being 2 bloom to 1 micro. You will start the nutrient solution at 1.2 ec (600 ppm on a hanna meter for example, 840 on another meter if it is associated with a .7 conversion factor). When the tomatoes drink enough water and/or evaporation due to sufficient aeration occurs to raise the ec to 1.4 you will top off with reverse osmosis, de-ionized or distilled water just enough to get the ec back to around 1.2. In my experience with 20 gallon containers, you could easily go 3 weeks under 50 watts hps per square foot until a complete water change is necessary. You do not top-off with anything but pure or nearly pure water, that means no nutrients. You do not know what ratio of contained nutrients in solution the plant is using so therefore you will likely achieve an imbalance by replacing nutrients when topping off. GH flora duo is meant to start with water of around 50-190 ppm (.5 conversion meter) so no need to start with distilled just make sure to aerate the chlorine out of the water before using it. The ideal amount of water to use per plant is as much as possible. You will find hydroponic gardening bliss when using 20 gallon containers per plant. They will be able to hold about 13 gallons of actual water. The smaller the container, the more headache you will encounter. Another thing that must be adhered to. You never use a rinky dinky 10 watt air pump with 1/4" airline tubing unless you strive for mediocrity. If you are using rock wool disregard that, but if you're using rock wool instead of submersed culture you do so for the sake of lesser results with greater work and expense (which makes no sense at all). If you want the best tomatoes you will need a sturdy 20 gallon container, a Danner pond master air pump (best on the market, there is no equal, many sizes to choose from, easily serviceable and not likely to unexpectedly break down if you change the diaphragm periodically) and 9" round air stones (only one manufacturer in the world makes them, Hydrofarm happens to be the distributor, they are unbreakable if cleaned in between cycles). After you achieve that set-up you will need an auto top-off system that is supplied by an RO or RO/DI or DI filter on demand (meaning no storage tank ). You will also need an outlet port of 1-1/2" pvc extending from 1/4" from the bottom of the water holding plant container so that a wet vac can be attached for draining to near dryness (works better than lifting the container by hand or dealing with an ever root clogging submersed aquarium pump). The same 1-1/2" outlet will be used to fill the container. A short length of clear 1-1/2" pvc in the vacuum adapter lets you know when your done draining. There is also a way to make the filling pump (when doing the water change) automatically stop filling when the correct liquid level is achieved, much the same way gasoline stops flowing from the pump when filling your cars tank. That's a little trade secret of mine that eliminates the need for dwc growers to re-enter the room for water changes during flowering.

Thanks for the advice everyone! I'm needing to fit these into the existing cabinet space, so I don't have the option of placing the microwave in a different spot elsewhere in the kitchen. It sounds like the swing-out door version is the safer way to go... will save us some money, anyway! Or could I do a microwave drawer under the wall oven? This may seem like a stupid question -- but how do tall items (like a cup filled with coffee) not fall over when the drawer is opened/closed? thanks! Michelle

I have a similar question, but mine is for our inground gunite pool with DE filter (pool is 18 years old, but we are new owners of the house/pool). We fired the professional company who overcharged us and didn't do the work. Here's our issue now: after multiple backwashes and adding DE, our filter pressure gauge is still reading 1, or zero. I'm assuming from the wonderful posts on this website that we need to get a professional to clean the filter cartridges, but should I turn off the filter until then? It's going to be 92 degrees here in SC today, so I'd rather not turn off, even with the slight trickle flowing in the pool. Thanks!

We have a double island kitchen with both island counter surfaces at 38" high. We also have a cleanup/scullery area with a farmhouse clean up sink that is part of the kitchen that also has the counter at 38". The separate side run of cabinets with the refrigerator and microwave is the standard 36" high in consideration of children and really short people. This area functions as a breakfast and sandwich area. My old house that I moved into 25 years ago had custom cabinets at 38" high b/c the prior owners were both so tall. Back then it was the only house available in our market and although I was appalled at what I thought was the way too high counters I just decided to live with it. Over the years I learned to love it and even had a cutting board in constant use that added another inch and half to that height. This is why the new house has the higher counters. One thing to consider is body proportions---leg and arm length vs. torso---in deciding proper counter height. Actual top of the head height doesn't tell the real story. Also, especially since I'm older now and my knees and feet not as resilient as in prior years, I wear a chef type clog whenever I'm prepping and cooking for an extended time. That definitely gives me an additional couple of inches of height. Finally, I am 5'5" maybe but everyone else in my family, DH and the children who all turned out tall, really appreciated the higher counters. HTH