In order to build homemade hydroponic systems, you'll need to have saved up some cash beforehand, as they can often get rather pricey, especially if you're going to get them everything they need: hydroponic light systems, ph and nutrient controllers, humidifiers and so forth. And if you're new in the field of DIY hydroponics, it's understandable that you would get a little spooked by rushing into building a system for the first time and spending so much money, without the guarantee that it will work like you're hoping it would. That's completely normal, as is looking for the cheapest build-your-own hydroponic system on the market if you're still inexperienced with them.
Money-Savers - Free Hydroponics Plans
One of the first things you'll need to start off your homemade hydroponic system is a plan to build it on. You could either go out and buy a plan at a store, or shop for one online, but you should also know that there are several websites out there that offer free hydroponics plans. They might not be as complete or as accurate as the plans you would get from a store, but they're definitely worth it for the price cut. And some are actually quite well designed. For example, two sites that I found quite useful in this sense are hydroponicsearch and simplyhydro, you might want to check them out.
Money-Savers - Components
You can purchase some of the components from your local store (Home Depot, Wallmart, etc) or order them online from Kalyx.com, our recommended hydroponics store.
In order to get the cheapest build-your-own hydroponic system, you will want to reduce your components cost. There are two ways you can do this: you can either replace some of the components that come on the price list with cheaper versions, such as getting a less powerful water pump, going for some normal glow lights instead of that expensive high intensity discharge metal halide lamp and so forth. Your second option would be to buy the right components, but at used states. Personally, I would recommend against replacing some components with cheaper versions, mainly because a homemade hydroponic system is usually based on a "component check" rule that only allows it to run properly if certain components satisfy the other components needs and vice versa. For example, in an ebb and flow system, if you buy a water pump that is too weak to flood the plant tray in time, even the small amount of water going in will drain back to the nutrient tank and your plants will have barely absorbed any water and nutrients in the process.
Money-Savers - Long Run Components
There are certain components that might not make your cheapest build-your-own hydroponic system all that cheap from day one, but in the long run could save you quite some money. One such example would be hydroponic led lights, which are equally efficient as High Intensity Discharge lights for small hydroponic systems, but they're a lot less power hungry, so they could save you a few numbers off that bill. PH and nutrient meters are also an early investment that can save you cash later on. Plants will depend heavily on the level of PH and nutrients in the solution you use to feed them and if they don't get a good PH balance or the right amount of nutrients, they will simply stop growing, rendering your entire homemade hydroponic system useless. By using a PH/nutrient meter, you can keep your plants happy at all times, thus saving your money in the long run.

Usually, stuff that's cheap is not that efficient and stuff that's efficient isn't very cheap. A dilemma you'll be facing when building a hydroponic system. Fortunately, there are a few ways to save up on cash, both in the short and long runs and this article will let you in on the secrets of getting the cheapest build-your-own hydroponic system.