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Growstones Secret GPGC1.25CF 1.25-Cubic Feet Growstone Hydroponic Substrate
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- Engineered to provide a highly effective balance between air and water content
- Growstones hold 3 times more water and 12% more air than Hydroton
- The perfect growing media for vegetables, herbs, fruit and flowering plants; from lettuce and basil to tomatoes, cucumbers, strawberries, and orchids
- For systems as simple as manually irrigated containers, or as advanced as automatically drip irrigated containers, Ebb-Flow systems, and NFT tables
- Manufactured using up to 98% recycled glass bottles
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|Item Dimensions||7 x 16 x 33 inches|
|Manufacturer Part Number||950HY125|
|Shipping Weight||15.6 pounds|
Growstone Hydroponic Substrate is the perfect growing media for vegetables, herbs, fruit and flowering plants; from lettuce and basil, to tomatoes, cucumbers, strawberries, gerbera daisies and orchids. It can be used in hydroponic systems as simple as manually irrigated containers, or as advanced as automatically drip irrigated containers, Ebb-Flow systems, and NFT tables. Growstones are engineered to provide an effective ratio between aeration and moisture. While other substrates maximize either air or moisture, Growstones allow for both moisture absorption and drainage. Most important in any growing medium is the air in the medium after drainage. Plant roots require oxygen for growth process respiration. Growstones make for an ideal substrate due to their small and large pores. When irrigated, water is held in the micro pores but quickly drains through the macro pores, allowing air to flow through the substrate, bringing oxygen to the roots and removing carbon dioxide from the root zone. Growstones are reusable. To reuse Growstones in a second crop, simply remove old plant material from the container and shake vigorously to displace most of Growstones attached to roots. If necessary, to get rid of the root ball (as is the case for crops with strong roots such as tomatoes) simply cut the base of the stem at the root ball level, and remove the root ball. Some Growstones aggregates will be clinging tightly to these roots and might be lost. Some finer roots actually grow into the aggregates and might remain attached to the media, but most will fall out. Add some new Growstones to replenish the system and replant again. Growstones are manufactured using up to 98% waste materials. They replace mined materials like pumice, perlite, clay pellets, and stonewool, reducing environmental degradation. At the same time, since the product largely consists of recycled glass bottles, a large amount of glass waste is given a new life, keeping it from the landfill.
Top Customer Reviews
I had also purchased a smaller quantity of hydroton to see how each worked for my grow.
The hydroton was easier at first- although it was much heavier in the shipping, broke through the inside bag, nasty red staining dust etc. and is more expensive. It rinsed ok. I used it for the 2" net cups as the grow stones seem better suited to 3" and above, (placed under/on top and around the transplantedrockwool cube).
The growstones shipped well (still dusty, but at least not red staining) and are much lighter to handle in the bag.
They do take a (one time) larger effort to rinse away/soak/rinse the dust and (one time only) adjust the PH from initial processing of the product.
My suggestion is to do it outside with a hose, in batches in a colander, from colander into a five gallon bucket, fill the bucket with fresh water, let soak the recommended time, take out by colander to re-rinse. I actually did that twice and it really was much less of a hassle than breaking open huge bales of promix, getting it wet, mixing in terra sorb, re wetting, mixing in compost & fertilizer etc. for my soil containers. Once you have the majority of dust off the growstones and they have soaked and are ready to use- that's it untill the season ends.
For my kind of Kratky method (non circulating) hydroponics they performed perfectly all season long.
I found that covering the top of the net cups (that were the only thing above the bin cover) with some taped down aluminum foil, kept the top of the stones from transpiring any moisture, reflected insects from the plant stem and stopped any light from entering the cups from above- preventing algae to the surface of the stones.
The stones kept it appears the perfect amount of moisture in the cups- the roots grew huge in the nutrient solution, stayed white and clean, and with NO Circulation.
I grew 37 different varieties of lettuce & 2 baby Pac Choi and a pickling cucumber in the bins (the cuke should have been in a bigger bin), and in the 6" net cup/bucket top for the 5 gallon buckets= I grew 2 varieties of 4 foot tall eggplant, a full size pac choi and a pepper. All were hugely successful and productive.
When it came time to break it all down for the year, I cut the roots off the bottom of the net cup and the plant remains off the top ( I left a stump of each plant still left in the growstones) and let them dry for a few days. I was able then to shake/pull off the roots from the growstones quite easily for the most part (a few thin roots left won't hurt), and I put he growstones in a bucket, disinfected with some bleach in water, drained and just let them dry in some good size uncovered pots on the porch (trays would have been quicker)- all ready for next year. I will probably still soak them next year just prior to planting, since they should be moist when transplanting the moist rockwool cubes into them.
Bottom line- if you desire to use rockwool cubes in 1.5" to 2.5" net cups- go with hydroton or actually nothing but the seedling bottom would work in such a small net cup. Anything else- use Growstones.
Hydroton is more expensive, MINED from the earth, manufactured by ? and by what process? The original company no longer manufactures & ships it to America....
Growstones are made from recycled glass, manufactured right here in the good old USA by an interesting process (shown on the Growstone web site). It's a no-brainer anymore for me. I will ONLY be using the 3" and 6" net cups from now on and just the growstones. This stuff was/is perfect for my Kratky style of non circulating hydroponic netcup container growing.
If you are interested in this style of hydroponics, go to you tube and do a search for 'Kratky Hydroponic'. The last movie I personally did, as a wrap up for the season, has a thumbnail of a bowl of my white eggplants, and the title that starts with 'What I learned- Outdoor Kratky Hydroponics'.
By the way- I filled (6) - 6" netcups and (30) - 3"' netcups with a bit more than 1/2 of this size bag.
Make sure and read the other comments here as well- many (but not all) are helpful. If you still have questions (as I did at first) go to the Growstones website and send them an email. They answered me quickly and nicely...so a good company as well.
The 1 star review is because the manufacturers are not up front about this fact. They hide it in their MSDS or in some fine print on their website, where most people won't see it, and they like to claim that it works for aquaponics. It doesn't, don't use it, go for a different media.
The first bag looks like the photo shown here on Amazon and the bag is made out of paper and on the bag it says to soak them for about 1-day, pour out the water in your garden and then rise the Growstones before use. The second bag which I bought is plastic and it says to rinse the Growstones and to put them into use. Those who have given Growstones a negative review commonly complained about them jumping the pH levels dramatically within their system, and I often wondered to myself if they followed the directions to soak them for 24-hours, rinse and then put into use. Seeing that there is two different bags says two different things here, has shed some light on this issue for me. I am showing both bags here in the photos below.
I myself am soaking the first bag of Growstones out of the paper bag in two 5-gallons buckets, with Gamma Lids (so I can screw the lid on the 5-gallon bucket down) so I could submerge the Growstones down into the water for the 24-hours. The second bag I am running the garden hose into the top of and poking a couple holes on the bottom of the bag for the water to run out of and flushing them by rinsing, and I will see if this makes a difference in the end pH of the water once they are washed.
In the end I personally liked soaking them the best, verses just rinsing them. Whether it has any basis to it or not, I felt safer with soaking and rinsing to ensure I got them thoroughly washed and cleaned right down into the tiny little pores. I got to thinking perhaps rinsing only washes the outside of the rocks, and 24-hours of soaking seems like a long time, but given the way they hold onto water I wasn't sure if soaking would help saturate the Growstones better with water, or if saturating the Growstones would help get out whatever has caused others to have their pH spike, and not wanting to take any chances, I decided to rinse, soak, rinse and then put them into my hydroponic drip system with pH balanced water. Following the directions I read somewhere I let my recirculation system run for a couple of hours with just the Growstones in it and nothing else, before trying to balance the pH once again, and then only after getting it to the desired pH balance I want did I add my plants to the system.
Upon learning some more about pH Down I realize why some people may say it took them a large amount of pH Down to bring the Growstones to a "Neutral" pH-7 level... One common name brand of pH Down is 5-times weaker than their competitor which is seemingly the much more common one in which every uses. Which would explain why some people could complain about the amount of pH Down product they needed to use to bring the Growstones pH Down to begin with.
The Growstones website says "pH neutral after preparation" and I've not had a problem once they were brought to a pH neutral.
How much Growstones are in a bag, I was able to fill two five gallon buckets within 3-4 inches of the top rim of the bucket from just one bag at 1.25 Cubic Feet... As far as their size goes I'd say they are around the size of a Quarter, and they are very light in weight. When I tried adding them to water they floated and did not want to submerge as I poured more into the 5-gallon bucket already filled with water, even when I tried to push them down to make room for more to go into the water they kept floating on top of the water. So I drained the bucket of the water filled the bucket with the Growstones and then filled it up with water and it wasn't until I reached the top height of the Growstones with the water did they begin to lift and float this time.
They may look smooth in the photos, but to handle them they remind me of a super fine grit sandpaper, and surprisingly suck up water amazingly fast. Which is one of the reasonings why they are suppose to be so good, because they have the ability to hold onto water with lot of little tiny pores within the rocks to hold air and water so the plants root system can use the water as it needs and not be swimming in water. This means you can water your plants less, or be safer in a hydroponic system if you have a failure of your pump because the roots won't be nearly as quick to dry out if something in the recirculation system were to break down. I also like the fact that because they are made some silica (glass) it is the silica type in which the plants can use.
As far as the price goes verses other hydroponic substrates out there, I felt these were the better choice overall because of all the benefits to my plants most of all, but also an added security for me for power outages and equipment breakdowns when I could loose my plants with other substrates that would be much quicker to dry out. As an added bonus I love the idea that they also provide my plants Silica, I'm saving the environment from more things in a landfill, and I'm not contributing to strip mining and ruining the beauty the Earth has to offer to future generations.
Now as far as my plants go, I personally think they are doing a lot better in the Growstones than I would have honestly expected from other hydroponic substrates I've used in the past, and I am happy with my purchase thus far since I haven't had any issues, but then again I was very careful to rinse, soak, rinse and follow all the directions I read for Growstones beyond just what I read on the bag. Perhaps this is where I have had better success than some others.