Q: What is the correct temperature range for the nutrient reservoir? My reservoir runs about 75 degrees, is this ok? How can I keep it in proper temperature range without the expense of chillers?
A: At 75° your temperature is running a little high, but not so warm that it’s guaranteed to cause you problems. The higher the temperature up to about 82°, the faster your plants will grow. But, at these higher temperatures the occurrence of root rot will be much more frequent. By keeping the temperature around 70° you’ll be somewhere in the middle, where you won’t get as frequent root issues, and you’ll still get fast growth.
Commercial hydroponics operations run their temperatures even lower at about 67° and can justify the slower growth by not having to lose plants to root rot. For hobby gardeners, I think a little more heat is justifiable to speed things up a bit, but over a long period of time, you’ll find that the lower the temp, the more stable your systems will be.
One way to cool the res down without a chiller is to keep several almost filled 2 liter pop bottles in your freezer. Freeze them with the caps off, then re-cap them and drop one at a time into your reservoir over the course of the day. This should bring your res down about 5° to 10° lower (depending on your res size) for a few hours. You’d have to do it several times a day, but if your temperature gets any higher than it currently is, it may be worth it. At 75 degrees, I don’t think you really need to bother with it yet.
Q: Your opinion on the need for CO2?
A: CO2 is huge. It’s number 3 in the level of “important things to a plant”, and that’s before fertilizer. Achieving and maintaining the natural levels of CO2 that are in the oxygen around us is the most important thing. Adding more beyond that will speed up the growth of a plant incredibly. The oxygen around us contains about 300 parts per million, but if you increase to about 1500ppm, the plants will go crazy.
Q: I was wondering on which light system I should get. HPS or MH… It will be used for Flowering plants… Some say HPS make plants grow lanky but promote flowering as MH is from start to finish. Does the HPS require a secondary light source?
A: I’ll have to start by saying that it is advantageous to use both MH, and HPS throughout the lifecycle of the flowering plant. Starting with the MH will achieve a healthier, stockier plant, more able to deal with the weight of it’s eventual flowers. Then, changing to the HPS will “fool” the plant into thinking that the season is progressing, causing a jump in natural hormones that forces the fruiting/flowering of the plant to take place more aggressively. That being said, if you just use the HPS throughout, you will probably achieve the same flower size or vegetable weight, but with lankier plants more in need of outside weight support. If you used just the MH throughout, the flowers would be smaller and more compact, but the overall weight of any vegetables would suffer slightly.
Many of the systems that we’ve got available are able to make use of both the MH and HPS bulbs within the same system. These have become the popular choice in the last several years, and they usually don’t cost much if any more than a devoted HPS system will.
Q: What’s the best way to set up a Can-Fan and Can-Filter combo?
You can set up Can Fan / Can Filter Combos in several different ways.
You can push or pull air through the filter, but the outer poly wrap is intended as a pre-filter to remove dust before it gets to the carbon, so it’s better to draw air up through the filter. The carbon inside will last longer with a clean pre-filter. The pre-filters are pretty cheap to replace, but you can hand wash them too as needed.
MOUNTING FAN AND FILTER:
We don’t recommend mounting the fan directly onto the filter, as the vibration of the fan can cause settling of carbon in the filter. This settling may allow air pockets in the carbon to develop at the top, and untreated air to pass through the filter.
You can hang the fan from a couple of rubber bungee cords to absorb any vibration and cut down on fan noise. Then connect the fan to the filter with standard clothes dryer ducting (from a hardware store) securing them together with either duct tape or screw-clamps.
The filter can then be placed in a dry location either sitting on the floor, or hanging from a ceiling. The length of ducting between the fan and filter doesn’t matter as long as the ducting is a clean, unrestricted shot between the two.
Straight PVC pipe can also be used for longer distances if necessary. For maximum effectiveness, the closer the filter is to the fan, the better, and we’d recommend keeping them within a few feet of each other. You can get some distance between them if you have to but it cuts down on the air speed.
AIR FLOW OPTIONS:
There are two really good ways to use the CAN combos.
The first is as a ‘polishing’ filter where you put the connected fan and the filter into the same area together. By drawing air through the filter repeatedly in a closed area, it will effectively keep the air in that area free of odors. This is how they use CAN filters in airplanes, and in other closed environments.
The second way to use the CAN combo is as a pre-exhaust air cleaner to remove odors from the air as you exhaust air from your garden area to another room. You’ll need a hole in a wall somewhere for this setup in order to exhaust the cleaned air out. All of the air that passes out of the room through the filter will be clean air. This setup is effective enough to use the heat from your growroom to help heat your home and not have to worry about organic fertilizer odor issues in the house. They use CAN filters this way in hospitals, auto body shops, chemical plants, and many other commercial applications.
GENERAL INFO:
All CAN-FILTERS last from 1 to 1-1/2 years – occasionally longer.
The higher your humidity, and the dustier the environment, the shorter the life of the filter.
To prolong the life of your equipment, clean the poly pre-filter regularly, and every once in a while shake or roll the filter around to expose new carbon within the filter.
If you find that you need any additional fertilizer odor control try ONA pro gel. It’s a good compliment to the CAN Combo if needed.
Q: I am a bit confused. If I want to apply Bat Guano as a fertilizer, should I do it during the total growing period or at specific times? Also, there are a zillion organic fertilizers, should I just throw a dart at the board and get one? They all sound about the same…
All fertilizers need to be used with some common sense, and organics are no exception.
Bat guano’s need some time to break down before they can be utilized by the plants. It may take up to 2 weeks for the guano that you’ve applied today to be usable by the plants unless you use a catalyst (or enzyme) to help break them down.
I think that in combination with other fertilizers, bat guano will give you many great benefits such as better flavor quality, and a greater resistance to insects and disease.
They promote a ‘living’ microbial environment for the plants’ root system, and the plants will benefit greatly from this, as well as a gentle, slow-release source of nutrients. If you just want to supplement your nutrients with the guano for these benefits, then they work great.
If you want to use the guano as your sole source of food for container plants, I’d recommend using an enzyme supplement like Earth Juices’ catalyst to compliment the guano, and quicken the release.
If you’re just looking to improve your overall flavor quality, and have a nice slow-release source of food for an outdoor garden, you could apply as frequently as once every 2-3 weeks, or most of the manufacturers would instruct you to apply once a month.
Q: What’s the difference between warm/cool bulb?
A. If you think of it in street light terms, the white ones are cool (metal halide) and the orange ones are warm (high pressure sodium). Plants are very spectrum sensitive, and pick up on different parts of the light than our eyes can see.
To a plant, the cool white lights simulate the brighter, whiter sunlight of spring and early summer, which is better for vegetative growth (more compact leaf and stem development).
The warm orange bulbs are more like mid-summer to fall sunlight, and actually cause the plants to ‘want’ to produce their fruit, flowers, or vegetables.
When you’re growing indoors, by starting out with the cool/white light, then changing to the warm/orange light, you’ll get a healthier, stronger, more productive plant.
Q: How long should I flood the ebb tray for, plus how many times per day?
A: There is no exact answer to this question, because everyone’s setup and environment are so different from one another, but here are some general guidelines. First, it completely depends on what kind of growing medium you’re using and your environmental conditions. If you’re using Hydroton rocks in containers, and your room temp is around 70 degrees, I’d go 4 to 6 times a day, at 15 minutes per watering, spread out around the clock (maybe not as frequently when the lights are off, but they still need water at night too). If you’ve got high humidity in the area, you won’t need this many waterings. If your temp is higher than 70, you may need more. If you’re using CO2, or add CO2 down the road, they’ll need more frequent watering then too. If you’re using rockwool, you’ll probably only need one or two 15 minute waterings per day, and only once every few days at first. Rockwool holds a ton of water, and usually people overwater it at first. If you are using rockwool, you’d want the blocks to start drying out a bit (not completely bone dry) before re-watering. This will force an aggressive rootsystem which will benefit the plant later on. Just don’t be afraid to try different watering cycles. You can still over or under water in hydroponics just like you can in soil, but if you really watch the plants (foliage and roots), they’ll let you know if they need more or less water. Figuring all of this out will eventually earn you your hydroponics green thumb!
Q: How do I control Spider Mites ?
A: Spider mite control is a popular (although un-popular) subject around here. The long list of products we’ve got to offer can be intimidating, but I believe that most all of our product offerings are great alternatives to the chemical sprays you’d find in the mainstream. I personally think that just about any of these can be effective when used correctly, and the approach you take to the treatment may be more important than the actual spray that you’re using.
Wait no longer than 3-5 days between applications:
Waiting no longer than 3-5 days between applications is, in my opinion, the main key to gaining control. Just keep going with the sprays every 3-5 days until after you know you’ve won the battle. If you wait any longer between treatments, that helps the mites to develop a resistance to your sprays.
Spider mites avoid the light:
Spider mites avoid the light, so they hang out on the bottoms of the leaves and stems, which is where you should concentrate your efforts with the spray.
For the same reason, turn your lights off at least an hour before applying any spray, because the dark will bring the mites out from under the leaves, to where the spray can hit them easier.
Use a variety of insecticides:
You’re doing the right thing by varying the type of spray. It’s probably best to change to a different type of spray after 3-4 applications of any one kind. Don’t completely give up on the sprays that you’ve already used, but keep them in your arsenal for future use.
Pyrethrin based spray (chrysanthemum flower extract) is probably the most common main ingredient for insecticides, and it can work well, but spider mites can develop a resistance to it so you have to use it with some reserve.
