There are sweet peppers (like bell peppers) all the way to extremely hot peppers (like habanero peppers). The heat difference is in the amount of Capsicum (Capsicum annuum) in the oil inside the peppers. Most people think the heat is in the seeds, it’s actually the oils that cover the seeds, so there partially right. But if you have ever rubbed your eyes after dicing up a pepper, you’ll know the pain was not because you rubbed a seed in your eye. Anyway Generally speaking the smaller the pepper, the more Capsicum (and heat) it’s likely to have. When deciding on a pepper plant to grow you should pick a pepper you are familiar with, and will be useful in your dishes.
When deciding to grow peppers (like any other plant) it’s important to take into consideration the size of the full grown plant, as well as the size of the root system. Peppers can be grown in a variety of types of hydroponics 
systems, though for larger plants, as well as when growing a lot of them, a drip system will probably be the most efficient.
Growing Hydroponic Peppers
Even within a species like bell peppers there are many varieties, commercial field pepper crops are usually determinate, the plant only grows to a certain size producing fruit along the way, then they stop growing, and eventually die. Indeterminate varieties require constant pruning to manage their growth in order to optimize yield for a given space, a balance between vegetative (leaves and stems) and fruit growth should be established and maintained. Indeterminate varieties don’t stop growing, they grow much the same way as tomato plants do. These types are usually grown in greenhouses and trained to grow upwards on a supporting trellis. The crop grows taller, this maximizes space and increases productivity for the crop.
Whatever type of pepper plants that you grow it’s important to consider the spacing, in order to maximize yield, but not so close that they are crowded. Pruning also improves air circulation around the plant which helps to reduce disease. Indeterminate varieties will need to be continually pruned (about every two weeks), because they continually grow new stems and leaves. Greenhouses usually keep them to 2 main stems growing upward from each plant. Indeterminate varieties can grow to a height of up to 4 meters (13 feet), and as mentioned will need to be supported. They are usually trained to grow on trellises made of twine. The twine is hung from the overhead support wires, and is used to support each stem. But be sure that the twine is not tied too tight to the stem, or the stem can be damaged when it expands as it continues to grow.
Flowering and Fruit Set
Though there are many varieties of pepper plants, they are generally a warm weather plant. Flowering and fruit set, as well as fruit size, are all related to temperature and fluctuations in the day/night time temperature. The optimum temperature for flowering and fruit set in sweet bell peppers is about 65-70 F°, while the optimum 24-hour temperature (24-hour average temperature) for yield is about 70-75 F°, and is more important to good fruit development. Unlike tomatoes, pollination of the 
pepper flowers occurs successfully without any outside pollination assistance from bees (in the correct temperature range), although additional pollination assistance from bees or other pollinating insects, as well as hand pollination has shown to improve flower set, and eventual yield and quality of the pepper fruit.
Deformed fruit is usually caused by inadequate pollination, this inadequate pollination can also be a result of temperature, but it can be caused by the light intensity being too strong also. The fruit themselves should be shaded adequately, either by the leaves or shade cloth for best results. However, the plants generally do not have trouble continuing to set flowers in less than ideal conditions. The root zone temperature is important also, if the root zone becomes to warm (above 72-75 degrees F°) the plants will tend to abort setting fruit, and the flowers will just drop off.
Even if the fruit is not perfect in shape and size, it still taste good and is just fine in your dishes. People are just used to seeing perfectly shaped fruits and vegetables at the market, but don’t relies that not all will grow perfect in nature. The rest get sold to companies that use them in other prepared foods. Do you know what the shape of that pepper was that’s in your pre-made salsa, or before they made the hot sauce with them?
Useful Links
Production of Greenhouse-Grown Peppers in Florida
Growing Bell Peppers in Soilless Culture under Open Shade Structures
Small Farms & Alternative Enterprises, pepper
