using dyna-roc for planting

[Hummer344]

For a number of years now I have used dyna-roc in my mixes. Two years ago I repotted a NOID phal in straight dyna-roc to see how it did while still maintainiing my normal watering methods. I flood my plants with a good amount of water every 5-7 days and use liquid fertilyser every two weeks(during the summer). Today I got curious as to how much moisture was retained by the dyna-roc so did some weight measurements. I weighed the plant prior to watering, after watering then after adding the liquid fert. I let the plant drain until it was a very slow drip(approx 10 minutes)
The dry weight of the plant was 2lbs 1.1oz.
After watering: 2lbs 5.8oz
After Fert. 2lbs 6.6oz.
The difference after watering was 4.7oz
the difference after fert was: 0.8oz.
Total moisture retention was 5.5oz

dyna-roc advertises that the material will absorb 150% of its weight but doesn't give any perameters. I am sure that figure is after soaking the material in water for x amount of minutes. The plant in question has survived fairly well although it seems to be a little more sensitve to light direction than my other plants.

Don't know if this is of any intrest to any one else but it shows me that my plant survies week to week with only 4.7oz of water.
david

[jay]

One possible reason your measurements were not a 150% increase would be there was moisture/water already in the dyna-roc. If you have been using it for some time now, there should be some water retained, even if it has been a week since last watering. To be more accurate, you would have to get a completely dry sample to weigh, then soak it for a prolonged period of time. Not sure if it would 150%, but very interesting.

You have made me curious. I think I might try this for Hydroton.