Case Studies

North Carolina State University
Raleigh, North Carolina
April 23, 1999

In July 1998, foam samples were sent to the Horticultural Substrates Laboratory for analysis. There were of one formulation, and three different configurations. They were configured as rooting strips, small wedges and large wedges. The same foam formulation was made into cylinders measuring 7.6 cm in diameter and 7.6 cm height (3 inches x 3 inches). These cylinders were analyzed for total porosity, container capacity, air space, and bulk density using the NCSU Porometer. The data for individual replications are listed in the appendix. A summary is a follows.

Total Porosity
91.6%

Container Capacity
61.4%

Air Space
30.2

Bulk Density
0.03 g/cc

Moisture content at saturation was 90% which was consistent with the porometer test. Almost all the moisture was the samples were released with very little pressure (1.0 kPa or 10cm). This indicated that the foam was extremely porous, and that the water held in the pours was readily available to the plant.

Results showed that the Aquos™ material was highly porous and should be suitable for product rooting and propagation.

Virginia Polytechnic Institute
Blacksburg, Virginia

October 14, 2002
Propagation Study
The Aquos™ growing media that we have tested at Virginia Tech is well aerated and well suited for propagating many types of plants from seeds and from cuttings. The material we have tested is inert and does not leak dangerous chemicals.

From my experience with using the Aquos™ product at Virginia Tech, I think it has good potential for applications where a well drained and aerated inert media is need to support good rooting, Inert substrates are commonly used in nutriculture (e.g. hydroponics) and are designed to provide mechanical support, proper root aeration and drainage.

Gregory E. Welbaum, Ph.D
Associate Professor
Department of Horticulture
Virginia Tech
Phone: (540) 231-5801
Email: welbaum@vt.edu

April 11, 2002
Water Leaching Analysis
We analyzed leachate from 4 samples. Sample J1060 was 11.9 g DWT or 11,2"x1" conical foam plugs, J1061 was 20.6 g DWT of 40,1"x1" cube plugs, J1062 was 15.8 g DWT of 4, rectangular cubes 2"x2" top by 2.5" x 2" side dimensions, and J1063 was 28.2 g. DWT 4, rectangular cubes 2"x2" top, 4:x2" side. Each ample was taken after soaking blocks for 30 minutes in one liter of extremely pure laboratory grade distilled deionized water, At the end of 30 minutes the blocks were squeezed by hand to removed remaining water.

The concentrations of heavy metals, total dissolved solids (after filtration with cheesecloth to removed the large particles) and nitrates were extremely low and well below the maximum tolerances for drinking water. The only factors that were out of tolerance for a drinking water sample were the pH (acidic) on two of the four samples and the "saturation index". The sample from the largest blocks had a pH of 5.2 which is pretty low. The other samples were (6.4, 7.2, and 6.9). Water is unbuffered and typically pH values very widely so the values were not that unusual, Natural soils (except for sand and low organic matter soils) are naturally buffered against pH changes and I would not expect this degree of variation from a homogenous soil. I think the variation in pH values may be an indication that the Aquos™ product is not well buffered against pH changes.

Keep in mind that the standard for these test are for drinking water which are very stringent and basically the filtered water coming out of your blocks was safe to drink. Some of the information may not be that significant because the runoff water from the blocks is not intended for use as drinking water. I think the good news is that the mineral content is very low.

April 11, 2002
Horticultural Technology Experiments to determine material leached from foam media blocks.

Treatment Code	DWT	Description
A - 11.68 Cheesecloth (Squeezed)	11.92g	11,2"x1" diameter conical plugs
B - 12.58 Cheesecloth (Unsqueezed)	20.55g	40,1"x1" cubes
C - 8.60 Cheesecloth (Unsqueezed)	15.83g	4, Rectangular cubes 2"x2" top 2.5"x2" Sides
D - 9.15 Cheesecloth (Squeezed)	28.16	4, Rectangular cubes 2"x2" top 4"x2" Sides

1 Liter of ddwater was poured over the blocks in a rectangular pyrex beaker. The blocks and water were allowed to equilibrate for 30 minutes. The blocks were compressed by hand to express loosely bound water. The leachate was poured into a graduated cylinder, stirred by shaking and 250 ml were filtered through 2-thicknesses of cheese cloth into plastic screw top bottles.

Water Quality Results - Sample No. J1060 Date of Sample: April 12, 2002
Test	Household Water Sample	Max Recommended Level or Range
Iron (mg/l)	0.009	0.3
Manganese (mg/l)	<0.001	0.05
Hardness (mg/l)	1.1	180
Sulfate (mg/l)	<0.3	250
Cholride (mg/l)	1	250
Fluoride (mg/l)	<0.1	2
Total Dissolved Solids (mg/l)	10	500
pH	7.2	6.5 to 8.5
Saturation Index	-4.96**	-1 to 1
Copper (mg/l)	0.0012	1.0
Sodium (mg/l)	1.1	20
Nitrate-N (mg/l)	<0.005	10
Total Coliform Bacteria	N/A	Absent
E. Coli Bacteria	N/A	Absent

Water Quality Results - Sample No. J1061 Date of Sample: April 12, 2002
Test	Household Water Sample	Max Recommended Level or Range
Iron (mg/l)	0.0066	0.3
Manganese (mg/l)	<0.001	0.05
Hardness (mg/l)	1	180
Sulfate (mg/l)	<0.3	250
Cholride (mg/l)	<1	250
Fluoride (mg/l)	<0.1	2
Total Dissolved Solids (mg/l)	5	500
pH	6.9	6.5 to 8.5
Saturation Index	-5.21**	-1 to 1
Copper (mg/l)	0.002	1.0
Sodium (mg/l)	0.22	20
Nitrate-N (mg/l)	0.098	10
Total Coliform Bacteria	N/A	Absent
E. Coli Bacteria	N/A	Absent

Water Quality Results - Sample No. J1062 Date of Sample: April 12, 2002
Test	Household Water Sample	Max Recommended Level or Range
Iron (mg/l)	0.0282	0.3
Manganese (mg/l)	<0.001	0.05
Hardness (mg/l)	1.5	180
Sulfate (mg/l)	0.636	250
Cholride (mg/l)	1	250
Fluoride (mg/l)	<0.1	2
Total Dissolved Solids (mg/l)	7	500
pH	6.4**	6.5 to 8.5
Saturation Index	-5.51**	-1 to 1
Copper (mg/l)	0.006	1.0
Sodium (mg/l)	0.69	20
Nitrate-N (mg/l)	0.155	10
Total Coliform Bacteria	N/A	Absent
E. Coli Bacteria	N/A	Absent

**Measured Value exceeds recommendation for household water.

Gregory E. Welbaum, Ph.D
Associate Professor
Department of Horticulture
Virginia Tech
Phone: (540) 231-5801
Email: welbaum@vt.edu

October 24, 2002
Germination Study
Enclosed are some picture and data from our study of different planting depths of cosmos and tomato seeds in Aquos™ foam. For the cosmos experiment we compared the Aquos™ product with Sunshine potting mix planted 0.5" deep. With the cosmos, the seeds germinated very quickly and we got the best emergence with shallow planting. Tomato seeds on the other hand were a little more flexible and they gave similar results when planted at several depths including 1.5". From these results, we have concluded that for faster germinating seeds, shallow depths like 0.5" works well while slower germinating seeds need to be planted a little deeper for best results. The best planting depth is very dependent on the watering system that is used. We watered the tray cells infrequently (once every two days). If more frequent irrigations are used or if sub-irrigations are used, the shallower plantings may be more acceptable. Conversely, the less frequent the irrigation, the deeper the planting should be since the water tends to collect in the bottom of the Aquos™ material and the upper layers become dry.

Table 1. Germination of mini yellow dwarf cosmos sowed in soil or foam for 4 days
	Germaination (%)	Wilting, 4 day drying (%)
Soil Sunshine (0.5")	81.6a	98.8a
Shallow (0.5")	60.1ab	34.8ab
Horizonitals (On Surface)	32.8b	46.6ab
Deep (1")	25.4b	0
P Valve	0.0212	0.0385
LSD	12.1	60.7

Table 2. Germination of tomato seeded in foam for 7 days
Depth	0"	0.5"	1"	1.5"	2"
Germination %	21.4%	85.7%	85.7%	92.9%	57.1%

North Carolina State University Raleigh, North Carolina April 23, 1999

Virginia Polytechnic Institute

North Carolina State University
Raleigh, North Carolina
April 23, 1999