Bests & Worsts Reviews from Amazon

I bought these pebbles for growing watercress as they are semi aquatic plants,and also bought Rockwell starter plugs to grow the seeds. The starter plugs were thoroughly whetted and inserted into the pebbles which were almost entirely covered with water. My seeds had 100% germination rate from what I can see, and the watercress plants are growing very well. When I started the watercress, i used water with half strength hydroponics plant food, and increased the plant food to full strength when the plants started growing.It was interesting to see that seeds I dropped on the wet pebbles also grew and new roots are growing into the clay pebbles. I should also mention that these pebbles should be rinsed well since they are covered in brown dust. I don't think it will hurt anything, but, in hydroponics, they will leave a brown sludge in the water. UPDATE 08/04/19: The 4th pictures is my crop of watercress that was taken about 3 weeks after the 3rd picture. I have already harvested quite a bit 5 times for 3 salads for my family each time and it keeps on growing. UPDATE 03/29/20: Since watercress is rated everywhere as the #1 healthiest green, I have been determined to grow it successful. The initial growth has always been great, but within 4 weeks, leaves started turning yellow, and the plants started to die. I was finding that I had to plant a new crop every 6 weeks or so. I did all the internet research that you have like likely done, only to find so many conflicting opinions. I had to figure out what I was doing wrong and what watercress needs for continued healthy growth. In studying the plants, I noticed the roots of the plants had become slimy and were dying. Without the roots, the plants can’t survive. I also noticed an extreme overgrowth of algae growth on the clay pebbles, especially as the plants started to die. The algae growth was hastening the demise of the watercress as it was consuming the nutrients required by the watercress. So, rather than believing everything I read on the internet, I used my knowledge of plants and considered the natural environment of watercress. 1) Watercress grow naturally on riverbanks and edges of ponds. So, the water around them is constantly moving and recycling to provide oxygen to the roots. 2) The water they grow in has to have a high nitrogen content provided by decomposing fish wastes and plant materials. This would contradict the information on the internet stating watercress doesn’t need plant food high in nitrogen. 3) Although watercress can grow in partially shaded areas, some sunlight is required for maximum growth., I am not growing watercress in only clay pebbles as the Rockwool promoted the growth of algae. I use 1020 flats, both with and without holes. The clay pebbles go into the flat with holes and this flat goes into a flat without holes. After putting the clay pebbles into the flat with holes and inserting into the one without holes, I fill the flat with water containing Fox Farm Big Grow plant food at 10 cc’s per gallon. Then I sprinkle the watercress seeds on top of the pebbles. I keep the water level below the top of the pebbles to discourage algae growth but spritz the pebbles once a day until the watercress seeds germinate. This usually takes 3-4 days. I add water with plant food and keep the water level t just below the top of the pebbles until the plants are established. Once the plants are about 2” tall, I replace the water once a week by pulling the top flat out, spraying the entire flat over a stationery tub to rinse of an algae that might have grown, dump the water in the bottom flat, and replace the water with a fresh solution of plant food mixed at 10 cc’s per gallon. So far, this has been working great. I can harvest and get new growth with no yellowing leaves. I have found that algae will grow on these pebbles when they are kept moist and are under lighting. When planting a new crop of watercress, the pebbles can be reused by first swishing them in a bucket of water to remove all debris. Then soak them in a 1 to 3 solution of bleach and water overnight to kill the algae and any bacteria. After the soaking rinse them well by swishing them in fresh water and draining a couple of times. Once this is done, they are clean and ready to use again. UPDATE 08/23/20: Although the watercress grows well for about 6 weeks in the flats, the roots require circulation of water to provide air to them. After about 6 weeks or so, the leaves started to yellow and I found the roots of the plants were rotting. A few weeks ago, I decided to try growing watercress, using these clay pebbles, in an AeroGarden Grow Bowl. I set the pump to go on for 2 minutes every 4 hours for the first 4 weeks, and then changed the pump setting to 2 minutes ever 6 hours. So far, this is the best crop of watercress I have had, and it just keeps growing with no yellowing of leaves. I have already harvested this watercress for quite a few of salads and steamed enough for veggies for meals a couple of time. I also gave away a gallon baggie full to a friend of mine. It has been growing for 81 days and so far, it looks as healthy as ever. I have added a couple of pictures of this crop of watercress. I hope this review was helpful for you.