Like soil-based plant growing, greenhouses offer a good alternative to the hydroponic gardener.
Many of the same advantages apply in either setting. But hydroponics is especially well-suited to greenhouses, where light, temperature and airflow are easier to maintain than in some other settings.
Tomatoes, peas, Welsh onions, strawberries and many other fruits and vegetables thrive in a good hydroponic greenhouse. Flowering plants like orchids are equally perfect for this environment.
One of the more challenging aspects of hydroponics is proper light control. Because the medium in which the plant grows is kept wet obviously so when the medium is itself water, algae growth can be a problem. Keeping light from reaching under the surface is easier in a greenhouse. The amount and angle of the light can be more easily controlled with shutters, shades and so forth.
At the same time, hydroponically grown plants, like their soil-based siblings, need ample light to grow well. Greenhouses don't by themselves produce more light. But they filter and diffuse it, keeping the interior warm and more uniformly lit. They protect the plants from cold exteriors but let in needed sunshine.
Many northern winter climates, for example, have low temperatures but several hours of sunshine daily. A translucent polycarbonate greenhouse wall can easily keep a greenhouse at 100F/38C even in winter temperatures of 15F/-9C.
At the same time, it's easy to install vents with fans that keep the greenhouse from getting too hot. Temperature control for hydroponically grown plants is just as important, if not more so, as it is for soil-based situations.
Utilizing a greenhouse to 'keep the benefits, exclude the harm' provides the best of both worlds. Without one, the only alternative might be using the inside of the home. Using the house can be a big disadvantage for some.
Among other things, a greenhouse - unlike some interior settings - allows for superior lighting and watering system arrangements. Few homeowners will want to give over a room to high pressure sodium or metal halide lamp fixtures. Not everyone will want drip irrigation systems running through the spare room.
With a greenhouse those elaborate systems can be placed precisely where and how it's best for the plants. That makes it more convenient for the gardener. That aspect is particularly important in the case of hydroponics, since light and water amounts are more critical than in soil-based gardens. Soil-based gardens tend to be more self-regulating without special setups.
By the same token, it's easier to arrange nutrient feeding systems in a greenhouse. That's critical in the case of hydroponically grown plants. Given reasonably good soil, plants will simply extract what they need and exclude what they don't. In a hydroponic setting that has to be arranged by the gardener.
pH control offers the same problem and greenhouses the same solution. It's much easier for the pH to shift in a hydroponic garden. Because water is everpresent, acidity and alkalinity can change rapidly by large amounts. Ions flow more easily in these circumstances. Working in a greenhouse allows the gardener to set up automatic pH control systems to reduce the amount of manual adjustment needed.
Greenhouses can be constructed or purchased pre-made. They make for an excellent investment for anyone interested in hydroponics. They come in a range of sizes and many are modular so they can be expanded as your garden 'grows'.