Due to some really inconsistent weather this year, our field grown lettuce was less than predictable so I made the investment into a 8-channel, 144 spot NFT system, a 4' x 8' x 7" flood table and a 4' x 4' x 7" flood table. The hope is to supplement our weekly farmer's market sales with 36 heads of lettuce each week.
The NFT setup is using a underground reservoir, which I thought would help with both algae growth and keeping the water temperatures down. I have a 1000gph pump which, surprisingly, is only getting me about 7L/m return at the drain pipe. Each channel is fed using (2) 1/4" microtube with an inline adjustable flow valve.
I will be using the smaller flood table to start my lettuce/spinach seedlings in 1.5" rockwool cubes then transfer them to the NFT once the roots are coming through the bottom. This tray will also double as a starting area for some of the other veggies in the Spring since it is quite an overkill since I will only be starting about 20 lettuce seeds each week.
Untitled by GhostPepperStore.com, on Flickr
Untitled by GhostPepperStore.com, on Flickr
I also have a 1000w MH light mounted centrally to provide supplemental light during the shorter days, I plan to keep it to about 14 hours/day. The greenhouse is heated and I keep night temperatures at around 62 degrees. Daytime temperatures, except in the Summer, stay below 85. I have invested in a pH meter and EC/TDS meter but at the moment I will be using tap water which is testing at 7.5 pH and 250ppm. I do not plan to change to RO water unless absolutely necessary.
(Those are 4 types of Rocotos, some hybrid Chinenses, and cumaris in those trays besides the rockwool)
Untitled by GhostPepperStore.com, on Flickr
So now for the questions.
This is my first time using rockwool. I sowed 8 varieties of lettuce, spinach and some herbs in the cubes on Sunday after soaking the rockwool in a 5.5pH bath. This morning, the cubes are still very wet. Is this normal? I realize the seedlings are not using any of the water yet, but since I will be giving these the flood and drain treatment, it concerns me that the cubes are staying wet for so long. The cubes are not covered since I have decent humidity in the greenhouse this time of year and it has been raining for the last couple of days to boot.
I know that for most NFT systems the recommended flow rate is 1L/minute per channel. I am not quite getting that rate at the moment, is this going to be an issue?
I am totally open to constructive criticism here, so please, if you see something wrong with my techniques, call it out.
(4x8 table with some stragglers that needed a couple of weeks to ripen remaining pods)
Untitled by GhostPepperStore.com, on Flickr
(Just for the heck of it, wilds gone wild, Chacoense, CGN 19198, Praetermissium, Parviflorum, Galapagoense and Flexuosum)
Untitled by GhostPepperStore.com, on Flickr
The NFT setup is using a underground reservoir, which I thought would help with both algae growth and keeping the water temperatures down. I have a 1000gph pump which, surprisingly, is only getting me about 7L/m return at the drain pipe. Each channel is fed using (2) 1/4" microtube with an inline adjustable flow valve.
I will be using the smaller flood table to start my lettuce/spinach seedlings in 1.5" rockwool cubes then transfer them to the NFT once the roots are coming through the bottom. This tray will also double as a starting area for some of the other veggies in the Spring since it is quite an overkill since I will only be starting about 20 lettuce seeds each week.
Untitled by GhostPepperStore.com, on Flickr
Untitled by GhostPepperStore.com, on Flickr
I also have a 1000w MH light mounted centrally to provide supplemental light during the shorter days, I plan to keep it to about 14 hours/day. The greenhouse is heated and I keep night temperatures at around 62 degrees. Daytime temperatures, except in the Summer, stay below 85. I have invested in a pH meter and EC/TDS meter but at the moment I will be using tap water which is testing at 7.5 pH and 250ppm. I do not plan to change to RO water unless absolutely necessary.
(Those are 4 types of Rocotos, some hybrid Chinenses, and cumaris in those trays besides the rockwool)
Untitled by GhostPepperStore.com, on Flickr
So now for the questions.
This is my first time using rockwool. I sowed 8 varieties of lettuce, spinach and some herbs in the cubes on Sunday after soaking the rockwool in a 5.5pH bath. This morning, the cubes are still very wet. Is this normal? I realize the seedlings are not using any of the water yet, but since I will be giving these the flood and drain treatment, it concerns me that the cubes are staying wet for so long. The cubes are not covered since I have decent humidity in the greenhouse this time of year and it has been raining for the last couple of days to boot.
I know that for most NFT systems the recommended flow rate is 1L/minute per channel. I am not quite getting that rate at the moment, is this going to be an issue?
I am totally open to constructive criticism here, so please, if you see something wrong with my techniques, call it out.
(4x8 table with some stragglers that needed a couple of weeks to ripen remaining pods)
Untitled by GhostPepperStore.com, on Flickr
(Just for the heck of it, wilds gone wild, Chacoense, CGN 19198, Praetermissium, Parviflorum, Galapagoense and Flexuosum)
Untitled by GhostPepperStore.com, on Flickr
I had posted in a couple of other forums earlier this week but I haven't gotten any responses. I will have to find my tin foil hat before I venture into the depths of reddit, but I really appreciate the tip.
