Fertilizing Seedlings
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Djolan
Location: Washington, Puget Sound Corridor
Posted: Apr-04-2005 at 11:45pm
Not sure how to look up this info and kind of wondering-
I use my aquarium water to water my terrestrial plants. I fertilize my aquariums.. Do I need to worry about because I'm constantly fertilizing them? Do I need to not use the aquarium water on my seedlings and instead use plain tap water? Will it change how I should go about doing normal fertilizing? It's not the biggest most pressing question, except for concern for my seedlings. I was curious though.
I add potassium Nitrate, Potassium Magnesium Sulfate, Potassium sulfate, and CSM+B. It's really just me being dorky, not sure if I need or even want to be as dorky with my garden as with my tanks...
cjmiller
Location: Oregon, Willamette Valley
Posted: Apr-05-2005 at 10:52am
I am just guessing, but I think that you shouldnt do that to seedlings, but probably just fine with other older plants. Just like you dont give wine to newborns.
Yes, not the best analogy.
Carol
basilgirl
Location: Oregon, Greater Portland Metro
Posted: Apr-05-2005 at 7:34pm
I wouldnt use fertalized water on seedlings.
growest
Location: Western British Columbia
Posted: Apr-05-2005 at 7:54pm
Djolan--I've never really heard of fertilizing aquariums, live and learn!
Sounds like that water would be fine for your seedlings, commercial growers do something similar called fertigation where they blend fertilizer with all their irrigation water, and the plants grow fairly optimally. Aprox. 200 ppm of nitrogen is the main thing they would watch for, plus keeping the overall salt equivalent level of the water below anything harmful, whatever that level is.
If you notice the roots of your seedlings being stunted and/or browning, rather than vigorous and whitish, you might want to use clear water alternately to "leach" excess salts...the pros have tools called conductivity meters to keep an eye on any dangerous buildups.
I doubt the aquarium would have harmful salt levels, or your fish, etc. would suffer. There is a system of aquaponics that shares a greenhouse with plants and a pond of fish so that the fish excrement can be cycled thru the plants and fresh water goes back into the pond...a natural cycle on a very small scale. Sounds like you're doing something a bit like that, which apparently works great.
My 2cents anyhow!
Glen
Djolan
Location: Washington, Puget Sound Corridor
Posted: Apr-05-2005 at 11:42pm
Glen, you had to say the magic words conductivity meter... I got my refractometer last week and started eyeing up orp monitors, conductivity monitors or a ph probe... a hobbyists daydreaming and shopping is never done
I fertilize the aquariums because they are super heavily planted, seems like the levels I kept in the aquarium consistently are nothing compared to what garden plants get though, just switched to a new fert method though.. I appreciate your response, it was really helpful and gives me a lot more things to look up.
I think I'm going to hold off til my seedlings have their first set of real leaves at least, they won't seem so frighteningly delicate then. The salts shouldn't be an issue, my hard water salty tanks don't get used on the ground plants. I was reading about a kelp fertilizer people use, wondering if the macroalgae I harvest from my marine tanks could be used for the garden plants, right now it's just getting tossed... anyway to link up to hobbies sounds good to me. The ground gardening thing's sounding way more relaxing right now though.. off to read about fertigation, ran across "foliar fertilization" or something yesterday I need to read more, much, much more.
growest
Location: Western British Columbia
Posted: Apr-06-2005 at 8:21am
Djolan--sounds like you'll do just fine with your seedlings...keep buying those gardening/aquarium toys,too!
Cutting edge farmers are actually growing algae (bluegreen type) then applying it to their fields...I think it fixes nitrogen like legumes plus it's kind of a slow-release fertilizer as it decomposes. Your algae I guess are more like kelp, growing in your saltwater tanks? Good stuff for gardens, people go to the beach and collect it to apply to vegetable gardens or compost piles. Might want to just rinse the salt water off before applying, tho our rains really do that quite well too!
Your right about gardening in the ground being more relaxing, you can get away with a lot more out in the garden than in containers or seedling trays esp.
The salts I was referring to is actually any kind of ions dissolved in the water, not just sodium chloride. The fertilizers you mentioned (added to your aquariums) are all actually salts, and will bump up the salt/conductivity readings in the water. If those levels build in the seedling mix, the roots will get stunted and even burnt, leading to poor or non-existent growth. It's always a balancing act with fertilizer, not enough won't give you much growth, but too much can really burn the plants, even kill em. The conductivity meter is used by commercial greenhouse guys all the time, to make sure it stays exactly at optimum.
An incredible reference, since you like to read, is called the Ball Red Book. It is the greenhouse plant growers bible, with exact recipes for growing each type of bedding plant, foliage plant, whatever is done commercially. I can find it at the local horticultural college library here (too expensive to buy unless you're in the business). This would give the conductivity reading you want to keep each plant at, for eg, plus temps night and day, days in each size container, ppm nitrogen that's optimal. Way more than most of us want to know!
Glen
Gardening for the Homebrewer: Grow and Process Plants for Making Beer, Wine, Gruit, Cider, Perry, and More
By co-authors Debbie Teashon (Rainy Side Gardeners) and Wendy Tweton