after coming back from my run this morning, i took a shower and had half a piece of danish. about 12:30pm i went to the dollar store to pick up a plastic pitcher for mixing my hydroponic nutrient solution.
after i came back, i tied the box of honey-can-do adjustable shelving unit to the back of my bicycle and pedaled down to the amazon hub locker in centra square. my item was too bit for the automated lockers and the scan machine didn't recognize my barcode anyway, but an associate came out from the back warehouse to scan and take the box for me.
from central square i went to market basket, via norfolk and hampshire street. i was making pita wraps the rest of the week, i already had the pita bread and chicken, just needed some lettuce and tzatziki.
i left for belmont around 2pm via motorcycle. i had all the materials i needed to start my mason jar kratky hydroponics project, and since the mustard seedlings have already started to show roots in the rockwool, it was time to transplant them into their mason jars.
i moved everything to the basement grow room to work. i first measured how much water i needed. i had 2 quart-size mason jars and a large hanging jar. the mason jars required 3 cups of water for it to come up 1/4 on the 3" net cups (for a total of 6 cups or about 1.4L). the large hanging jar required 8 cups of water to come up to the same level on a 3" net cup. i took pH and EC measurements on the tap water. mustard green likes a pH between 6.0 - 7.5 and an nutrient EC of 600-1000ppm. the pH value for my tape water fluctuated, as high as 9.46 and as low as 8.70, so an average of pH 9. i wasn't sure how accurate my pH reader was, and i couldn't calibrate it with the pH buffer powders because i didn't have any distilled water. the EC reading for tap water was 91ppm. out of curiosity, i went outside and tested the rain water: pH 6 and EC 16ppm. i decided to use rain water since it had an optimal pH value.
the next hurdle was how much hydroponics nutrient powder to use. i was using general hydroponics maxigro (10-5-14). the recommended value is 5-10 grams per 4L of water. i decided to use the smallest amount - 5g to 4L of water, and did some math to figure out 1.4L of water required 1.75g of maxigro powder. i got the kitchen scale and realized something: the lowest value was 1g, i couldn't get anything in the decimal range. i did the best i could, figured i'd slowly add to 2g and then reduce a pinch to get about 1.75g. i dumped the measured nutrients into the pitcher of rain water and took new readings: pH was now 3.5 with an EC of 1200ppm! later i found out that maxigro nutrients has a tendency to lower the pH. so in my case, pH 6 to pH 3.5, a 2.5 drop. had i known i would've just used tap water (pH 9 to pH 6.5). i could've diluted the solution but that thought did cross my mind. instead i figured i'd get some pH up and down chemicals and adjust the nutrients accordingly.
for the larger jar, instead of using all tap water, i used half tap water and half rain water. the pH was 7.7 and the EC 65ppm. after adding the maxigro powder, the new pH was 5.27 and the EC 758ppm; still not optimal but better than the mason jars.
assembling the kratky hydroponic was a simple matter of putting the wet rockwool with mustard seedling into the net cups and using soaked leca balls to hold it in place. the two emerging rockwool seedlings i put in the mason jars, while the rockwool with the yet-to-emerge seedling (though i could see it already germinated inside the hole) i used on the larger jar.
everything looked good and i put the jars underneath the led grow light, until i remembered i forgot a crucial step: covering up the jars so light can't shine into the nutrient solution, otherwise i'd get an algae bloom and that'll kill the roots. fortunately i had some crumpled brown paper packaging material that i used to make jar covers. with that i finally set the jars underneath the grow light.
i also want to use the white led grow light strips instead of the blurple grow light, because the blurple light is way too strong and i just need a bit of bright light to grow the mustards. the blurple would be better suited for my eventual aeroponics experiment hopefully i can build this coming weekend.
this whole hydroponics business took me nearly an hour. originally i also wanted to go to home depot to get some aeroponics supplies (like PVC tubes), but i can do that later in the week. i returned home by 4pm.
so today was my first real introduction into the world of hydroponics. i learned some important lessons that i didn't know before:
- tap water has a high pH! at least in belmont (pH 9), where we get our water from the MWRA - which comes from the quabbin and wachusett reservoirs. rainwater on the other hand has a lower (more acidic) pH of 6.
- so on the flip side, even though rain water is more acidic than tap water, it's actually cleaner, and doesn't have as many impurities as tap water: tap water EC 91ppm, rain water 16ppm.
- a kitchen scale isn't going to work for measuring hydroponic nutrient amounts. i need a precision scale, which i've seen before. i thought they were silly at first, and figured they were drug paraphernalia (like "spice grinders" or fancy glass smoking pipes), so i never thought i'd need one.
- hydroponic nutrients change the pH of the water! like in the case of maxigro, it will drop the pH by 2.5.
- i need to get pH adjusting solutions. i could play around with dilution, but adding chemicals that can tweak the pH level up or down is an easier solution.
for dinner i made a pita wrap using the leftover barbecue chicken from yesterday, combined with some romaine lettuce, chopped red onion, and a generous serving of tzatziki. eating it was a real mess, but the taste seemed similar to a gyro, without the slices of lamb/beef.
i started watching shining girls, after my mother already finished the series this past weekend. it's not bad, but elizabeth moss seems typecasted as the young woman brutalized by the men around her - see mad men, the handmaid's tale, and the invisible man. i'd love to see her doing something against type, like being in a comedy, or an action film.
while taking out the garbage, i saw a girl going up to the house, trying to jiggle a key to go upstairs. are you the daughter? i asked her. she said yes. apparently she came to take care of her parents, who are in tough shape apparently. i knew michelle twisted her ankle early last week walking their dog while jeff was away on a business trip, but their daughter now tells me that jeff managed to contract covid while he was in seattle.
maybe it was because i heard that c-word, but i came back inside the house and immediately did a home covid test. not so much because i was afraid of contracting it from my neighbors, but i was done at the boston carnival parade this past weekend, and there was people everywhere. it's almost like i'm trying to get the coronavirus. anyway, did the test, got a negative. i think i may have my mother's immunity, which seems to be naturally resistant to covid.
before bed, i remembered i had to get a few more hydroponic materials. i went onto amazon and bought a precision pocket scale: the MAXUS elite digital gram scale ($11), weighs up to 200g (7oz.) with 0.01g precision, it's listed as "amazon's choice" for digital scales. i like that it has a cover that i can close up to protect the weighing bed. as for pH up and down solutions, i was leaning towards general hydroponics set of pH up/down, $20 for a quart (32oz.) each. but that seems like way too much chemicals for what i need, so i ended up going with standard hydroponics pH up and down kit ($16), 10oz. of each. it's about a third less than the general hydroponics brand, but it does come with 2 pipettes, saving me from having to buy them as well. the scale arrives on thursday while the pH up/down will be here friday.