Ask the Professor – Prev. Questions 6

Professor –

How fast can plants grow in hydroponics?

Sabin

Sabin –

This question is just about impossible to answer. The rate that a plant grows depends on several variables. Amount and quality of light, the amount and quality of water and nutrients, the genetic make up of the plant, etc, etc……..I can’t tell you exact numbers. Generally speaking – a plant will grow faster hydroponically because it doesn’t need to grow extensive root systems do to the fact that everything it requires is supplied directly to the root system. The plant can therefor spend its energy growing more vegetation instead of roots.

P.H.

Professor –

I have been feeding my plants Bumper A and B nutrients I maintain a constant pH. of 6 checked and adjusted daily. My Question is; How important is it to monitor the ppm of the nutrients? The Bumper system only asks that I maintain a pH of 6. I have been changing my nutrient every 17 days.

Tyler

Tyler –

I am not personally familiar with this particular nutrient, however, as a general rule of thumb it isn’t terribly important to monitor the nutrient strength. What I recommend about changing the nutrient solution is this – When the level of the nutrient solution drops a 1/3rd of its volume add straight water (no nutrients) to bring it back up to full. Re-adjust the pH if necessary. Repeat these steps when the level drops 1/3rd of the volume again. When the nutrient level drops a third of the way for a third time change the nutrient solution completely.

P.H.

Professor –

Hi! I was wondering if it was possible if you could have many plants in the Hand-Watered Bucket or Water culture system using different mineral nutrient for each on or do I have to have a separate bucket/tank for each one? I am doing my science project on hydroponic and what does the effect of different amount of nutrients have on the effect of the plant’s growth.

Hsiao-Ting

Hsiao-Ting –

You will need a different bucket / tank for each different nutrient solution. There could be more than one plant per bucket but all plants in that bucket would have to receive the same nutrient solution as the roots of the separate.

P.H.

Professor –

I am interested in hydroponics and would like to try a kit. I’ve been reading about it but am not sure where to start. Would you recommend a kit for a beginner who wants to grow vegetables? I would like to place it on a screened in balcony and use natural light. Any suggestions?

Carole

Carole –

If you are into “do-it-yourself” you can find several small system plans. CLICK HERE to view them.

If you are looking for a “store-bought” system we have several listed in our catalog: CLICK HERE to view the small systems, or CLICK HERE to view some that are a bit larger. Any of the above systems (except the Professor Hydro’s science kit) will work to grow vegetables on a balcony as long as there is ample light.

P.H.

Professor –

I’m looking for a nutrient formulation for herbs which will give me the best growth rate over the range. I grow parsley, thyme, oregano, marjoram, rosemary, basil, coriander, dill, mint and garlic chives, on a homemade table with capillary matting. I guess its a bit like a modified NFT system. the herbs are grown in a 2 to 1 perlite & vermiculite mix in 10cm squat pots.

thanks for any help you may be able to provide.

Simon

Simon –

Any good “grow” formula (high nitrogen) fertilizer should do the trick.

P.H.

Professor –

Would you please E-mail me a list of the compounds w/proportions necessary to grow plants in a hydroponic system? I’ve looked almost every where unsuccessfully and have a science project due in the near future.

Tyler

Tyler –

The elements commonly used for hydroponic nutrients are listed below along with the limits and average amounts used in common nutrient solutions. All values are listed in ppm (parts per million).
Nitrogen- limits 150 – 1000 average 250
Calcium – limits 100 – 500 average 200
Magnesium – limits 50 – 100 average 75
Phosphorus – limits 50 – 100 average 80
Potassium – limits 100 – 400 average 300
Sulfur – limits 200 – 1000 average 400
Copper – limits 0.1 – 0.5 average 0.5
Boron – limits 0.5 – 5.0 average 1.0
Iron – limits 2.0 -10.0 average 5.0
Manganese – limits 0.5 – 5.0 average 2.0
Molybdenum – limits 0.01 – 0.05 average 0.02
Zinc – limits 0.5 – 1.0 average 0.5
The source for this information is a booklet entitled “Plant Nutrition –
Theory and Technique”, which is a very informative publication by Green Air Products,
one of the leading manufacturers of hydroponic fertilizers.

P.H.

Professor –

I think you website is outstanding. Thanks for free plans, etc. I have several problems. My hydro. units contain stones and is Ebb & Flow with 10 gal water in each unit of 4 units. It’s quite a project to clean. I’m going to try 1 gal. buckets with one 24 oz. solo cup filled with stones and one plant in each bucket. Do you think I will be successful? I don’t want to spend more money–too much in it already. I also had big problems with gnats and white flies. I tried whitefly predators without success. Any suggestions? Also, I was cleaning units and found sewer cockroaches (about 1/4″ in size). Any suggestions to prevent this. Thanks for your help.

Bernice

Bernice –

I believe that your idea may work fine as long as the root system doesn’t get too cramped. It should be ok as long as the plants aren’t real large. The whitefly predators don’t usually help much unless you are in a very controlled environment and even then I haven’t seen much success. Whiteflies are very difficult to get rid of, but with some persistence it can be done. There are several products on the market that help control these little pains-in-the-butt. They are all organic and safe for humans. Safer’s makes a couple of products that I would recommend, Safer’s Insecticide soap and Safer’s Bio-Neem which contains Neem oil. (Note: Bio-Neem is also a repellant that keeps pests from coming). We also sell a product called Exclude which is an aerosol that is made of natural Pyrethrum which is a extract made from chrysanthemums. All the above products are organic and can be applied up to the day of harvest. The most important thing to remember is that the treatment is a contact killer so it needs to be done once a week for three to five weeks, otherwise new bugs will hatch out and the problem returns. By applying the insecticide 3 to 5 weeks it will break the entire life cycle of the pests.

P.H.

Professor –

I am trying to use the hydroponic system to “clean up” the water of my fish tank. if it is possible…, what hydroponic system is best for it? I will be very grateful if you can send me the drawing of the hydroponic part as I have NO knowledge about hydroponic.

Black

Black –

I don’t have any real experience with aquaponics (which is what they call combining fish raising with hydroponics), I have an interest in aquaponics and we have a local customer that is experimenting with it. This customer has been raising fish for food and is trying to combine it with hydroponics. The link below will take you to a great site that is devoted to aquaponics, it should be a big help. CLICK HERE for aquaponic link.

P.H.

Professor –

Its getting cold what temp should I keep my nutrients at? Will an aquarium heater work? Also what is a pH that most plants do well in(5.5 to 6.5?)?

Bryan

Bryan –

The nutrients should be kept at about 72°F. An aquarium heater is perfect. In fact that is what we sell to do the job. Generally you need to keep the pH at between 6 to 6.5 (5.5 to 6 if you are using rockwool).

P.H.