Which one is it? A question that every newcomer to hydro gardening has. The answer isn’t as simple as the inquiry though. It depends on the system you’re going to use, and over time you will probably try out different kinds based on suggestions made in forums, blog article opinions, and the stuff the local hydroponic store clerk recommends. Sometimes, it’s not which particular media is best, but which blend. Seasoned growers many times have a mix they’ve developed that they prefer.
Then there is the quest for the cheapest growing media. The more new grows you start, the more attuned you become to the mounting cost of this part of your indoor garden materials. A tighter rein on the budget is pretty normal today, so a lot of new soilless growers are happy to learn that some media is reusable. This means you can save money without reducing the quality of your harvest. The best three types of hydro media for getting started all fall into this recyclable category.
Yes, there are a number more professional, and hacker options. Some, like lava rock (a.k.a. red or black cinders) will bring you complications that a beginner really shouldn’t have to overcome. This stuff is cheap, no question about it, but due to it’s porous nature will create rising pH issues in your system. Don’t shoot yourself in the foot before you get going. It will be less expensive in the long run to go with the least likely to create drama and extra work.
Keep Your First Grow Simple!
Stick to the basic mediums: perlite, hydroton (clay pebbles, hydrocorn… all the same stuff), and coconut coir. Which one will be the best one for you? The system you have will greatly matter there. The chunkier texture and rounded surface of expanded clay pebbles gives your crop’s roots increased drainage and air flow, or aeration. Perlite and coir are much finer textured, creating density, which translates to lower aeration, increased moisture retention, and can grow algae or mold nicely if irrigated too much.
Like everything else, there are both advantages and disadvantages to each type of hydro garden media. Reduced moisture retention means your system needs to irrigate root zones more often, but the re-oxygenation factor you get with hydroton also gives you a faster growing crop. In turn this will reduce the amount of hours of basking under your grow lights between vegetative stage and harvest. The pump in your system uses far less electricity than the lights, fans, C02 generator, heating, and cooling that is part of any grow room… so a faster finish translates into indoor gardening at a savings too.
Cleaning the medium for the next crop is also a garden task to consider before deciding what medium to use. Sterilizing is the easiest part here, that only involves soaking the stuff for a while. You also need to remove all the old roots to keep your media inert. Picking them all out of perlite is tedious and messy, because roots love this material so much they will be entwined throughout all of it. Coir, also being dense, won’t prove to be a simple material to clean either. Hydroton on the other hand will be much easier, and faster to recycle thanks to it’s larger pieces that don’t compact from root pressure.
One Last Note
We don’t want to forget about gravel. Pea gravel, aquarium gravel, small cheap gravel… it seems to be a popular cost cutter approach to getting going in hydro gardening. You’ll have more luck with this in aquaponics beds where worms can keep it free of plant debris. It will get down there, no matter how hard your work at cleaning it up, and create a totally different form of havoc for you to overcome.