Help with T5 Fluorescents, pH-EC meter and Fertilizers

by Rob

I'm a novice/intermediate that's growing habaneros, jalapenos, and small-fruited determinate tomatoes in containers indoors. I have a 4 ft., dual bulb T5 Tek light and a 2'x 4' grow area lined with Mylar.

1) For seedlings and the vegetative stage, would it be better to use two 6500k bulbs, or one 3000k and one 6500k bulb? For the flowering stage, would it be better to use one 6500K and one 3000K bulb, or two 3000K bulbs? I don't have money for a HPS or MH unit.

2) Can you recommend an affordable, user-friendly digital pH/EC meter? I've browsed a few on, but maybe you have a better source.

3) And if you could grace me with your knowledge with a more complex issue regarding fertilizers, I would greatly appreciate it...

I need a detailed fertilizer regimen for germination, seedling, vegetative, flowering stages. I will follow your basic potting mix recommendation, but what I really need to know is how to incorporate my nutrients. How often to add them, when to add them, at what amounts, etc. I have the following nutrients:

Neptune's Harvest Fish Fertilizer 2-4-1
AGGRAND Natural Fertilizer 4-3-3
AGGRAND Natural Kelp & Sulfate of Potash 0-0-8
AGGRAND Natural Liquid Bonemeal 0-12-0
AGGRAND Natural Liquid Lime Plus Calcium & Magnesium

P.S. - In the past, my jalapenos and tomatoes set fruit, but I have yet to see a habanero. I'm thinking they require more heat and humidity than my apartment can offer. My apartment temps. range from a constant 70-77 F day and night. Can lack of fruit on my habaneros be from not having night temps in the 60s? Do chile plants need to be pruned? Thanks, Rob

Answer: Rob- for clones and the veg stage, I would recommend using two 6500K bulbs. Veg plants require less light than flowering plants to grow, and the extra blue light in the spectrum will help keep your veg plants nice and compact (short spaces between branch nodes). When you switch to flowering, you have a choice to make. Using one 6500K bulb and one 3000K bulb will provide a little blue light and keep your flowering plants from stretching so much. However, 3000K bulbs put out more usable light per watt than 6500K bulbs- and flowering plants require more usable light to grow properly than veg plants. Plus, flowering plants prefer the 3000K (more red) color spectrum. If you are working with a plant variety that does not exhibit a tendency to stretch a lot, I would recommend using two 3000K for flowering hands down.

On a side note, Google "HPS security light"- you may be surprised at how affordable some of them are! (Although the T5's should really be just fine).

The most affordable way to cover both your pH testing AND your EC testing needs is to do them separately. For about $7.00 you can pick up a General Hydroponics pH test kit from your local hydroponic gardening store. I believe you can also get them through mail order from Alternative Garden Supply, and possibly Discount Hydroponics. In a pinch, you can go to a pet supplies store and find a pH test kit in the fish aquarium section. For keeping your EC in check, go to and search for "truncheon"- you can probably find it in other places too, if you search for it....but $40.00 altogether, including shipping, is about the most affordable EC test meter I have ever come across. I believe there are a couple of affordable Hanna EC test meters, but not as affordable as the truncheon at ecrater.

Seeds started in plugs or trays can be given a weak dose of the 2-4-1 fish fertilizer. Follow whatever recommendations are on the bottle for seedlings. If there are no recommendations for seedlings, a 1/3 strength solution (of whatever they consider "full strength") should be just fine. Only fertilize when the plants truly need the water.

Always keep track of the numbers associated with the fertilizer you are feeding (for future reference- this becomes important).

After 10-14 days, seedlings can be transplanted into small pots (4 inches). Try not to put them into pots that are too big- this leaves lots of soil that does not have roots in it yet, and makes it very easy to over-water. If you are using a soil mix with FoxFarm, worm castings, and other organic nutrients, you may want to give them plain water. If you have made up a soilless mix of peat, vermiculite, and perilite (with no nutrients in it), you can give your plants a 50% strength solution of the 4-3-3 fertilizer. Continue with this regimen until roots begin to appear from the bottoms of the containers, than transplant them into 8 inch containers or one gallon pots.

It should be safe to give them full strength doses of fertilizer after this point. Continue using the 4-3-3 fertilizer until the plants begin to flower. If under natural light, this will probably be sometime in July. Keep a careful eye on the leaf tips for the earliest signs of fertilizer burn- if the very tips of the leaves begin to burn, you know you have reached the upper limit of what your plants will tolerate fertilizer-wise....the next time they need water, give them plain water- and from than on, be careful not to exceed that particular rate of fertilizer application.

If the plants are in the new containers for more than a couple of weeks, and they still have not begun flowering, you may want to move them into 2 or 3 gallon containers- or you may want to plant them outside. When flowering begins, they will need more Phosphorus to produce fruits. Begin fertilizing with the 2-4-1 fertilizer again....with a couple of small changes- add a small amount of the 0-0-8 to boost the Potassium level a little (this will provide stronger branches to support the weight of the peppers), and also add a small amount of the Calcium & Magnesium supplement (this will help ensure each flower becomes a pepper and grows healthy). Once again, do not exceed the fertilizer level which you recorded/were using just previously to flowering....and continue to keep an eye on your leaves.

There is enough Phosphorus (the middle number) in the 2-4-1 fertilizer that the addition of the bone meal should not be necessary. However, if you find yourself flowering your peppers and they are a super, super dark green, you may want to reduce the 2-4-1 in your formula slightly and replace it with a splash of the bone meal fertilizer....again making sure to stay within your previously recorded fertilizer limits.

Peppers prefer hot (80 degrees) relatively dry be careful not to over-water them! From what I can gather in the gardening forums, habaneros often do not even flower until late August or early September, and than they begin setting fruit and can continue through November. From several different discussions, I believe the habaneros are more day-length sensitive than other pepper any ambient light hitting the peppers when they are expecting it to be dark would trick the plants into thinking it is still July, and prevent them from flowering and fruiting normally. For a crash course in how to fruit plants that require a dark period, make sure to read my flower forcing page. From what I can tell, the fruiting is not dependent on hot weather or warm night-time temperatures.

Finally, I don't believe there is any reason to prune your pepper plants, unless they are getting ridiculously tall, or unless the very bottom leaves are looking very old and beat up. I hope this helps you out Rob, and Happy Growing!

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