Posts published on June 2010

What is the difference between HPS and MH? (the difference between cool delux, neutral delux, and warm delux)


b3_1_bBoth the Metal Halide (MH) and the High Pressure Sodium (HPS) are HID grow lights (High Intensity Discharge) which provide many benefits

when compared with conventional fluorescent and incandescent lamps. Supplemental HID lighting enables commercial growers to increase crop yields, deliver crops to market on schedule and produce crops entirely out of season which can be very financially rewarding.

HID lighting is so efficient and powerful that many indoor growers profit from its use year round.

Being a HID is about all the two different bulbs have in common. There are also different types of conversion bulbs that will work on either MH or HPS ballasts and can be had in a wide variety of spectrums from 3000k to 10,000k. Although the conversion bulb seems like a great and ideal bulb, it loses at least 20%, up to 55% of the typical lumen output of the same wattage bulb due to the conversion process.

The Metal Halide lamp provides more of the blue/green spectrum, which is ideal for leafy crops, and/or plants that are in a vegetative (actively growing) stage.

Also MH lamps provide a more natural appearance in color (mimicking the intense summer sun) and are typically the choice for plants that have little to no natural light available. HPS lamps on the other hand provide the grower with more of a yellow/orange/red spectrum.

Another benefit is HPS lamps have good spectral distribution mimicking the shorter fall days, which is ideal for most plants that are actively fruiting and flowering.

In addition, HPS lighting is the choice for growers looking to supplement natural sunlight. Ideally, the horticulturalist will use MH to grow their plants and HPS and flower their plants because each has the needed specific spectrum of light.

High pressure sodium bulbs stimulate flower and fruit production in plants more efficiently than any other grow light source.

The best grow light is not one but both used in conjunction. Another big plus about the HPS (high pressure sodium) bulbs is that they have a much longer life expectancy (20,000 hrs) compared to Metal Halide Bulbs.

Written by Joe at San Diego Hydroponics.

Can I use a HPS for veg?


Fluorescent-LightTraditionally fluorescent lighting is used for vegetative growth, seedlings, cuttings and plants with low light-level requirements

and HIDs are used for established plants and or plants that are larger with higher light-level requirements.

Fluorescent lighting technology, however, have provided more options for horticulturists.

T5 fluorescent lighting is the latest in plant growth lighting. T5’s high-light output combined with its low heat and energy consumption makes it an ideal light source to grow a broader array of plants. They also use less electricity and with rising costs for electricity these days less watts equals a lower monthly bill.

In response to the general question, can you use an HPS bulb for veg, the answer is yes.

However I have pointed out better and more efficient ways to veg your plants. Basically you can use just about any light out there for any stage of growth, the real question is how well do each bulb work for veg.

The best bulb for veg would be a Metal Halide HID light.

The MH provide superior spectrum and penetration to your vegging plants making it the ideal and most sought after veg bulb. The second best in my opinion would be T5 Florescent lighting. These fixtures are newer tech than the T8 or T12 floroscent bulbs because they are the best type of florescent light in regards to lumens per watt, penetration and considerably less heat.

Written by Joe of San Diego Hydroponics.

What is the difference between magnetic and digital ballasts?



The digital or electronic ballast is the latest in ballast design and innovation.

Digital ballasts are more efficient, quieter, cooler, and softer on the bulb and they do not have any of the usual transformers, capacitors or igniters; instead these ballasts use electronic circuitry to do the same job, more efficiently with little to no heat. What might take a standard coil/magnetic ballast 680-700 watts to fire a standard 600 watt bulb, may only take a digital ballast only 600-620 watts to fire the same bulb to the same brightness.

The old coil type ballasts are hard starting ballast which means when the ballast fires the bulb it sends full power to a cold bulb.

Over time, this shortens the bulb life and reduces the PAR (PAR represents the plant usable light; it’s what plants “see” and use, versus lumens which are what people see) output of the bulb. Digital ballasts start by sending a low amount of power to the bulb and then steadily increase the power over the next few minutes until the bulb has reached full brightness. This technique is also known as soft starting, which minimizes the damage to the bulb and increases its PAR life.

After one year of use the plant usable light coming from bulbs that are run on digital ballasts has decreased only by 20-25% where as the same bulb being used in the coil type ballast would have lost 50-60% of its plant usable light over the same period of time.

Coil type ballasts are also known to cause the bulb to flicker or strobe. This takes place so quickly that the neither human eye nor light meter can pick it up. This is because of the Hertz range (Hz) that the coil/electronic ballast is outputting to the bulb.

The older coil style ballasts will typically output at 60hz where as the digital ballasts provide a uniform power supply to the bulb, at about 200hz, thus eliminating the flickering from the bulb.

A great feature of digital ballasts is the ability to run both MH and HPS bulbs on the same ballast without having to flip a switch. Digital ballasts are “intelligent ballasts” and most are able to recognize the difference between the two types of bulbs and fire them accordingly. Because of the high starting power requirements of some bulbs (such as the Solarmax) digital ballasts cannot always fire these bulbs due to the soft starting feature inherent to digital ballasts. Nor do digital ballasts fire multi-vapor bulbs.

The good news is that the majority of bulbs in our industry work just fine with digital ballasts.

However, digital ballasts have a great safety feature that helps to prolong the ballast’s and bulb’s life. If the bulb is defective or incompatible and does not fire, the ballast will only attempt to fire the bulb after a predetermined amount of time and shutdown if unsuccessful. Digital ballasts will also shut down if there is a short in the system.

When purchasing digital ballast, the consumer must be aware that there are different manufacturer’s and that not all digital ballasts are created equally.

There are many inferior quality digital ballasts on the market so be sure to get the best digital ballast available! At San Diego Hydro we recommend the Global Green House Digital ballasts as they have been proven and tested for over four years and are the industry standard when it comes to electronic ballasts.

Written by Joe of San Diego Hydroponics

How to Kill Spider Mites



There is a better approach on how to kill spider mites.

Besides damage control, there are other preventive measures for you to use like biological, water, and mechanical controls or the more aggressive means of chemical control.

Biological Controls

Biological control is established in the hierarchy of animals within the food chain. Dark lady beetles of the Stethorus species and big-eyed bugs or pirate bugs of the Geocoris species are natural enemies of spider mites. These beetles and bugs instinctively know how to kill spider mites. There are even mites which prey on fellow mites. Modern technology also artificially manufactures insectaries to combat spider mites. When we interfere with this natural chain of events by using sprays with carbaryl or malathione, we kill the very organisms that protect us against spider mite outbreaks.

Control Using Water

Watering your plants regularly not only protects your plants during dry weather but it also prevents the laying of eggs among spiders by delaying the production of webs. An occasional, directed blast of water to clear foliage of dust would be a forceful way on how to kill spider mites in areas where spider mites’ enemies would naturally abound. Spraying a plant every day with ice water for one week is claimed to get rid of spider mite inhabitants. Let it be your way of giving spider mites a cold shoulder.

Mechanical Control

A mechanical control on how to kill spider mites would be to destroy webbing. Walking on eight legs is no problem with spider mites. It allows them movement in all directions and angles. Webbing lets spider mites travel sideways or drop down and slide up from leaf to leaf. Higher temperature and wind sway webs in the direction of other plants, giving way to further widespread infestation of spider mites. Imagine how some ninja fighters or Special Forces action units make a quick and quiet ambush or getaway, and that is how this would look.

Chemical Control

Miticides are specific pesticides used against mites, including spider mites. Some species of mites, however, have become resistant. Besides, miticides do not destroy eggs and spraying has to be repeated every 10 to 14 days. Otherwise, the spider mites return to resume their activities.

Cheaper methods on how to kill spider mites would be to use botanical or horticultural oils derived from the neem tree which prove gentle to plants but lethal to mites or through insecticidal soaps and isopropyl alcohol with dish washing suds regularly sprayed on the underside and veins of leaves where eggs are usually laid. These, too, would have to be done on a regular basis.

Having approached the problem from the biological, water, mechanical, and chemical point of view, this time you are well-prepared and equipped on how to kill spider mites. A balanced combination of all these preventive measures would be the best way.

N-P-K Explained


npkN-P-K is the simple abbreviation for Nitrogen-Phosphorus-Potassium.

These nutrient  values are always written in that order. These three nutrients are represented by numbers and are reported on every fertilizer sold is the U.S. Typical example: 3-12-10. These numbers are referred to as primary elements. Choose high N fertilizers for evergreens and non-flowering / fruiting plants. Use fertilizers with high P-K values for flowering or fruiting plants. Nutrient bottles should also be properly labeled with micro nutrients also included in the formula.

There are two types of fertilizers: organic and inorganic.

Organic fertilizer is composed of carbon-based organic matter. Inorganic fertilizers are made of inorganic materials such as peat and mineral deposits or synthetic versions created in a laboratory. A trend toward organic fertilizers has erupted due to the increasing number of environmentally friendly and health conscious gardeners. Those who wish to increase their plant yield use inorganic fertilizers due to its rapid effects on growth over organic nutrients.

How to sprout seeds



Starting Seeds is a great way to start out your gardening season disease and pest free.There are a few key factors involved with starting seeds, timing, medium, temperature and moisture.

Choose your timing so that your seed starts don’t overgrown before its time to plant outside. Overgrown seed starts are difficult to get back on track.

Most seed packets have a planting schedule on the back to help indicate proper timing. Some seeds like to be soaked for a period of item before planting. Soaking time can also be found on the back of the seed packet.

Using a light and airy medium is crucial…

for new seedlings to develop roots. A light peat or vermiculite base medium without heavy fertilizer that will hold moisture is best. After choosing your container fill almost all the way, lightly soak your medium and place either one seed per space or evenly space seeds apart sowing smaller seeds a few in one spot is ok too. Lightly sprinkle your medium on top of your seeds and use a squirt bottle to evenly spray with water.

It’s important to keep your seeds evenly moist throughout germination

Using a squirt bottle is an easy and effective way to moisten seeds without over doing it. Using a fertilizer is not necessary while still germinating. When seeds begin to sprout giving them a mild fertilizer and some mycorrhiza for positive root growth is ok, however most seed starting mixes have enough food in them to get your seeds through out the sprouting phase.

Keeping your seeds warm will help them germinate quicker.

It is as easy as setting them close but not on top of a heater vent, putting a fluorescent light over them or getting a heat mat from your local garden store. Keeping them above 70 degrees and below 85 degrees is best.

When it time to plant your seedlings make sure you take the time to acclimate them to the outside temperature. Putting them outside in a shady spot for a couple hours the first day and slowly a day at a time introducing them to the sun will ensure your seedlings don’t get (sunburned). This is called “hardening off”. Plant them on an overcast day or in the evening to prevent transplant shock.

Worm Tea


We give out Free Worm Tea every week!

Highly nutritious worm castings are an organic super food for plants. Alive with microorganisms and beneficial bacteria, Worm Tea provides plants with the nutrition they need to increase production and boost nutrient content.

When used as a foliar spray, Worm Tea protects both the plant’s health and eliminates existing diseases.

Bring in an empty gallon container to your nearest San Diego Hydroponics store and let us fill it up for you free of charge! Your plants will love you for it!

For more indoor,outdoor, and hydroponics information, please visit San Diego Hydroponics & Organics website.

Tips for Preparing a Planting Bed


dirt_soil_lgIf you are preparing beds for landscaping around your house this article is for you.

Let’s assume that the area where you are planning your bed is now planted in grass. How do you get rid of the grass? Chemicals or no chemicals?  Chemicals are easy, so we’ll look at the chemical method first.

My favorite chemical for killing grass and weeds is RoundUp, and used properly it is effective.

Rule number one: Read the label on the package, and mix the chemical exactly as recommended by the manufacture.

Rule number two: Assume that every plant that the RoundUp touches is going to die. It is a non-selective herbicide.

The first thing you need to do is mark out where your planting bed is going to be.

Spend some time on this step. If you are landscaping around your house, give careful consideration to what is going to be planted in the bed, and then decide how large each plant is going to be when fully mature.

You can keep plants trimmed to a certain size, but be realistic when you make these estimates. Trust me when I tell you, this is the number one mistake made by do-it-yourself landscapers. People are just afraid to make those beds large enough.

Typically, a bed should never be narrower than 42”, and corner beds should be 12’ in diameter. Islands. If you make those little tiny island beds that I see everywhere I am going to come over to your house and snap you with a wet towel! The island bed in your front yard should be 20’ to 40’ long, and a minimum of 12’ in diameter on at least one end.

The easiest way to mark out your planting beds is to buy a can of marking paint at the hardware store.

Unlike most spray paint, this only works when the can is inverted, and it is designed specifically for painting lines on the ground. They even have cans that spray chalk instead of paint. I’ve always used the paint, it holds up better if it gets wet.

Once you have the outline of the bed established and marked, mix up some RoundUp and spray all the grass and weeds inside the bed area. Do not put RoundUp in a sprayer that you intend to use for other purposes. You need a sprayer that is dedicated for the use of herbicides. When applying the spray, be very careful not to let the spray drift onto the grass and other plants that you do not want to kill.

To minimize spray drift, adjust the spray nozzle so the spray pattern is narrow and the droplets are larger. A wide, fine spray pattern is sure to drift outside of the intended area. Also keep the pressure in the sprayer quite low. Pump it just enough to deliver the spray. High pressure causes the spray to atomize and drift. Apply just enough spray to wet the foliage. If you have liquid dripping off the blades of grass, you are applying too much. More is not better.

Once sprayed, be careful not to step in the area that has been sprayed.

Many a people have had golden foot prints across their lawn because they forgot and walked through what had been sprayed.

This is the difficult part, and the part that many people do not get, so pay close attention. The only way that the RoundUp can possibly work, is if you leave it alone. Did you get that? Once you apply the RoundUp, don’t do another thing with that bed for 72 hours. That’s three very long days. I know you’re anxious, but this is the price you pay for not planning ahead.

RoundUp is a systemic herbicide, which means that it has to be absorbed by the plant, then trans located throughout the plant. It takes three days for that to happen. If you go digging and chopping, you might just as well skip the spraying step. Go build a compost bin while you’re waiting.

After three days the weeds and grass are going to look as healthy and happy as ever. Don’t let em fool ya. They’re as dead as dead can be. Providing the RoundUp didn’t get washed off by rain within the first 24 hours of the waiting period. Now you can dig and chop to your heart’s content.

However, the only digging that I do is to go around the edge of the bed and strip the sod back about 15”. Just peel off about 1” and flip it into the center of the bed. This makes it easier to edge and mulch the bed if you get the sod out of the way. Now for the non chemical method.

Mark out the outline of the bed as described above. Strip the sod back 15”, just like above. Since you aren’t using any herbicides I would dig down about 1-1/2” when removing the sod from the edges. Take the sod you stripped back and lay it in the center of the bed upside down and pack it down firmly. Now take newspaper or brown paper grocery bags and cover the entire bed area. Use 9 layers of newspaper. No matter what method you used, chemical or non chemical, you are now ready to fill the planting bed with topsoil.

Put 8 to 12” of good rich topsoil in the bed. Make sure the soil is higher in the back, closest to the wall, so the water drains away from the building. If you are creating an island planting make the center of the bed the highest point. Make sure the topsoil you buy is well drained and rich in organic matter. Buying topsoil is a tricky game, you’ve got to be careful and shop around. Topsoil is one item that you do not want to order over the phone, sight unseen.

This is what you are looking for when buying topsoil:

Topsoil that is rich in organic matter will be very dark in color. If the soil is light in color it is probably just fill sand. The other thing you’ve got to watch for is how well drained the soil is. Topsoil that has a clay base is poorly drained and sticky, and your plants will not be happy at all. They might even die if they are too wet. Once a clay based topsoil dries out it gets very hard.

Today most topsoil is run through a screener to remove the clumps, rocks, roots, and sticks.

There is nothing wrong with buying unscreened topsoil, especially if you’ve visually inspected it, and have found it to be of good quality. Actually, really good topsoil shouldn’t have to be screened, but there is little of that quality topsoil to be had.

When you visit the yard where the soil is stock piled, scoop up a handful of the topsoil and run it through your fingers. If it seems to be grainy, it is probably good soil. But if it appears to tiny round balls, that can be smashed between your fingers, it is probably a clay based soil that will trap water during rainy seasons, and get as hard as a rock when it’s hot and dry.

Pay attention to how the soil is screened. Some machines just shake the soil over a set of screens to separate the debris, and others actually shred the soil. If the soil needs to be shredded, you don’t want it. Look closely at the pile that the raw soil is coming from. If the soil in the raw pile is as hard as a rock, that’s what the screened soil is going be once you get it in your beds. If it appears to be fairly loose, it’s probably good soil.

Put 6-8” of topsoil in your beds.

How to Grow Hydro


hydro-garden-sept-2008How to Grow Hydro

Through the water, the plants will receive all of their food. This water needs to contain primary nutrients (N-P-K), secondary nutrients (calcium, magnesium, iron, sulfur), and all trace nutrients.

How to grow hydro with supplements In addition to regular food, there are a few additives that make a huge difference in the healthy development of your plants.

Many expert gardening articles I have read by people who know how to grow hydro recommend adding Thrive Alive B1 and Maxicrop to every drop of water you give your plants. Use 10 ml (2 tsp) per gallon of each. If you are using a seaweed based fertilizer, it is not necessary to add liquid seaweed.

Nutrient Solution Ph

If you want to learn how to grow hydro well, you must know about Ph. The nutrients are only good to the plants if the Ph is right. The maximum nutrients are available to the plants in a Ph range of 5.5 to 6.5. In hydroponics, the nutrients are often kept at about 5.5 because the plants absorb the nutrients slightly more quickly at this Ph.

Also, the natural tendency is for the Ph to creep up over time, and so it is your natural tendency to adjust the Ph down to the low end of the range when you make an adjustment.

Nutrient Solution Strength

People that know how to grow hydro use a total dissolved salts (TDS) meter or an electrical conductivity (EC) meter to tell how strong or how weak the nutrient solution is. The ideal strength of your nutrient solution depends on what type of plants you are growing, and also what stage of the plant life cycle they are in. Check this section out to find out what strength to keep your nutrient solution.

Maintaining your Nutrient Solution

In a ten gallon reservoir, you will need to check the strength (TDS or EC) and the Ph of your solution twice a day. With a larger reservoir, the changes in the nutrient solution take more time. I would still recommend you check your nutrient solution once a day, no matter what size reservoir you have. People that know how to grow hydro usually use a larger reservoir.

If the Ph is up, than add some Ph down. It is a good idea to check the Ph first, because the addition of Ph down will change the strength of your solution a little (TDS or EC).

If the nutrient strength is a little weak, add a little fertilizer. If the nutrient strength is a little high, add plain water. It is a good idea to let water sit out overnight in an uncovered container. This lets the water dechlorinate, and also lets the water become room temperature. Adding cold water will shock the roots, causing root damage as well as above ground damage.

Change it Every Two Weeks

After two weeks of using the same nutrient solution, it is time for a nutrient change. The plants may have been using some nutrients more than others, and now you might be heading for a nutrient imbalance. Keep an extra nutrient reservoir full of plain water waiting for your next nutrient solution change. This ensures you will have dechlorinated, room temperature water that will not damage your plant’s roots.

It is a good idea to run a tank full of plain water (or 1/4 strength nutrient solution) for a day in between nutrient changes, to flush out any nutrient buildup. Some experienced gardeners do this every four weeks, or every other nutrient change. During every nutrient change, consider using hydrogen peroxide to keep things clean and healthy.

Once you have a simple feeding plan that is working well, you can try to maximize your results.

The best advice here is to make small changes, one at a time, and to let each change show its effects before making another change. Sometimes this will mean waiting two weeks, other times it may mean waiting a whole crop cycle for the results.

My experience has shown that a simple plan with high quality results is what your goal should be. Many times, experimenting only leads to bad results. To make matters worse, if you changed two or more things, you have no idea what is causing the problem now.

The Final Flush

Pros that know how to grow hydro usually do a final flush just before harvest. This can be done by replacing the nutrient solution with plain water for the last 7 to 10 days. It will help if you change the water each day with fresh, plain water for these last few days.

Flushing the crop helps remove any fertilizers in the plant tissue. Flushing will improve the flavor and aroma of the produce in your garden.

Controlling Aphids with Ladybugs


ladybugControlling Aphids with Ladybugs

Aphids are tiny insects that feed on everything from strawberries to flowers in your garden. They’re small, pear-shaped insects that have a unique characteristic: two tubes called “cornices” that protrude from their posteriors. Aphids are destructive, because they feed in colonies and they multiply rapidly. Each new aphid embryo is born with a tiny secondary embryo in it. In other words, aphids are born pregnant.

How to Tell You Have an Aphid Infestation

The first sign of infestation is that the aphids create colonies under the leaves of plants. When aphids feed on the plants, they leave a residue coating on the leaves. This residue coating, called aphid honeydew, develops into a black or brownish fungi. Eventually the plants begin to wilt and die after aphids feed on them. To get rid of the fungus you must get rid if the aphids.

Ladybugs: Natural Aphid Predators

Ladybugs work as a natural pest control for aphids. Ladybugs typically have yellow, orange or red shells with black spots. They have a black head with two antennas on them. Each ladybug will eat about fifty to sixty aphids per day. The female ladybug will lay about fifty eggs per day, and each ladybug larvae will consume about thirty aphids in a day. Ladybug control is one of the most effective ways to get rid of aphids.

A common mistake most gardeners make is not recognizing ladybug larvae. A ladybug larvae looks like a tiny six-legged alligator, with blue-black coloration and orange spots.

When you use ladybugs to wipe out aphids, you will have a continuous supply of ladybugs, assuming the aphid propulsion does not fall too rapidly.

Besides aphids, pollen is another part of a ladybug’s diet. They feed on pollen before they get ready to hibernate. Here are some plants that ladybugs thrive in:

* Calendula (Pat Marigold)

* Chives

* Cosmos

* Marigolds

* Statice (Sea Lavender)

Ladybug Dispersal Tips

The difficult part concerning ladybug dispersal is keeping them in your yard. Most gardeners make the mistake of releasing ladybugs during the daytime.

If you release ladybugs during the daytime, they’ll use the sun for navigation and leave your yard.

The following tips will you keep ladybugs firmly in your yard:

* Place the ladybugs in the refrigerator for a few hours.

* Water your garden and lawn where you plan to release the ladybugs.

* Release them before sunrise or after sunset. Releasing them in darkness ensures they will stay on your property and attack aphids.

* Remember not to squish or destroy ladybug larvae.

* Lady bugs need pollen to thrive, so make sure your garden has flowers.