Are your grow lights on? Are you sure? Maybe your timer, ballast or lamp is failing right now and you're sitting here reading this article! I'm not trying to make you paranoid, but experience has taught me that indoor grow gear fails—fans burn out and air stones quit bubbling. And to make things more complicated, we cannot predict which items are going to break down next or when it's going to happen.
If you take your garden seriously, you won't mind paying for insurance in the form of some spare gear. Here are several items that occasionally fail and some suggestions for dealing with—or even preventing—catastrophes.
Lights are the heart of your garden and the key to your plants' growth—if your lights go out you've got to get them back up and running as soon as possible.
If you are running HID or fluorescent lights like most indoor gardeners, the lamp or the ballast can fail. The best option is to keep spare grow bulbs and ballasts on hand, but that can be expensive.
A second, less ideal option is to keep some shop lights (four foot T12 fluorescents) around—you can hang these inexpensive fixtures in place of your broken grow light while you go to the local hydro store for some troubleshooting. Shop lights will maintain your garden's day/night cycle temporarily, although your plants will stretch and grow poorly under these weak lamps, so make sure you get your real grow lights working again as soon as possible.
In my hydro systems I always use two pumps: one large pump to run the system and a smaller pump that sits in the reservoir and stirs the solution. Since I incorporate some organic supplements in my nutrient solutions, dirty or clogged pumps are inevitable.
Pumps are one of the only products that have decreased in price at hydroponics stores. Fifteen years ago, I would pay $60 for a pump for an ebb and flow system, but these days it's more like $25. Admittedly, higher-quality pumps can be purchased for a higher price tag and they might offer a better warranty—for a spare pump, though, the lower-cost option is acceptable.
If you use air stones, you know that they eventually clog and stop bubbling. I have seen the same growers replace their air stones again and again over the years I've worked in hydro stores.
Let me save you a few bucks. There is an easy way to use the same air stones for years without replacement. First, you will need to buy the heavy air stones, not the thin brittle ones. Second, you will need two air stones for every one that sits in your reservoir.
Each time you change the nutrients in your reservoir, remove the wet air stone and replace it with a spare. Clean the used stone with a scrub brush and let it dry out completely—drying reduces clogging from microbes and algae. The newly cleaned air stone will now become the spare, ready for the next reservoir change. You will always have an air stone in the reservoir and a clean, dry air stone waiting in the wings. This process will keep your solution bubbling steadily for years.
Grow room circulation fans
Wall-mounted fans, oscillating fans, desk fans—we all have them in our grow rooms. Unless your grow room is very, very small, you should have more than one fan to gently ruffle the leaves. With multiple fans, a single failure is no big deal—just get a replacement fan within a day or so and your garden won't skip a beat.
If you are just using a single fan to circulate the air around your garden, though, you should consider having a spare. If your only fan breaks you run the risk of hot spots and powdery mildew, as well as reduced growth.
Grow room inline fans
Spare gear is great, but blowers and inline fans are too expensive to have spares sitting around. But if you are cooling your lights or garden space with a blower, what happens when it goes kaput? Do temperatures rise to the point of wilting your prized flowers? This is another time to reach for the shop lights—turn off your hot HID lights and run shop lights in this emergency scenario. The heat will be drastically reduced while you run (don't walk) to the grow store for a new lamp or ballast.
Grow Room pH meters
Small pH pens can give you a digital readout on the acidity or alkalinity of your hydroponic solutions, but they usually only have a one-year warranty. If your pH meter stops working you might not be able to replace it right away—and most likely you'll be standing over a fresh batch of nutrient solution when it goes out.
A great spare pH meter is the 'drop test kit.' These kits include a small beaker and a bottle of dye. You scoop up a sample of solution, add a few drops of the dye and shake it up. The solution will change color and indicate the pH. The downside to these low-cost kits (usually less than $10) is that they aren't very specific—they can only give you a ballpark reading. Also, if you use organics, your solution could be too dark for the dye to take effect. In that case, digital is your only option, so get a new meter soon as you can!
Hygrometers and thermometers
Digital and analog thermometers and humidity gauges are available at garden stores and other retail shops. I recommend having at least two of these units operating in your grow room—ideally, you should get two different models from two different manufacturers.
After a few months of use, you might notice that one meter reads drastically differently from the other. This is an indication that one meter is failing—get a new meter and compare readings with the first two, then dispose of the faulty unit. Remember—an ounce of prevention is worth a pound of cure.
I hope my failures can lead to your successes. If you know what's likely to go wrong, you can be prepared with a quick fix. And when its time to upgrade your garden, keep the old lights, pumps and so on for backups.
Be diligent, hope for the best and plan for the worst. If something goes wrong, don't freak out—just fix it.