Hydroponic growth stages..

[John]

Can you give me some idea on the various growth stages (in inches) on some of the more common vegetables i.e.
tomatoes, peppers, lettuce, kale etc. My system has been running now for about two weeks and I have nothing to gauge my
progress against.

For instance my tomatoes from which I started from seed on 3/16/97 are about 5 inches tall now on 4/17/97. They look
healthy with purple stems and purple under leaves (is this purple coloration normal?), but for some reason I think they should
be growing faster - especially when I see Ron's web site pictures. I also have some cayenne peppers which are about two
inches tall with two sets of leaves - I started these from seed on 3/23/97.

Does this sound like a proper growth rate. My lettuce seems to be doing good as well as the summer squash. The kale also looks good (started from seed on 3/23/97 - about 3 inches tall now and the leaves are getting bigger). My system is based on Ron's 2 liter soda bottles ( I have 16 bottle system.

On 4/7/97 I placed the system under with the plants under a 1000 watt metal halide light. My medium is pea sized river bed
gravel. I'm using formula one nutrients with an EC of 2.5 milliseimans.
Any info or comments will be greatly appreciated.

[Ron K]

There are several important things to consider for good, healthy hydroponic plant growth:

A balanced, hydroponic nutrient formulation is the best way to go - especially for beginning through intermediate gardeners. The TDS level is also extremely important as is maintaining the nutrient solution pH at a level acceptable to the plants grown.

For example: beans and tomatoes require TDS from 500ppm (when seedlings) gradually increasing to around 1500 when maturing and fruiting heavily. An acceptable pH for these plants is 5.5 to 6.5.

If using a liquid formula it should be at least a 2 part formula to contain an adequate amount of sulfur and magnesium - something that single part formulas neglect because of chemical combination problems.
Aeration of the nutrient solution and plant roots is very important as well.
Healthy roots should be white.

Adequate feed frequency is important too. In ebb & Flow systems feed often. This may vary with temperature, size of plants, etc. but I've found that feeding every couple of hours for a long enough period to fully saturate the roots works very well. If a growing media with good aeration ability is used it is hard to "over water" because the roots will be properly aerated to provide the very important oxygen they need.