flowering with aquaponics, revisited

**haole420** · 09-04-2012, 07:12 PM

last season was a disaster. whiteflies took over the coco grow. inadequate filtering and nutrient precipitation fouled the roots on the aquaponic side and i my plants prematurely died a few weeks early. i had to keep most of the harvest for myself, but i gotta say, considering all the shit that went wrong, it wasn't bad! couple things i learned: (1) go with a higher res volume/plant ratio, (2) don't use citric acid as a pH down, (3) keep the pH in the ideal range for the plants, not the fish, and (4) filter the solids out of the system.

the aquaponic cloner, which was the first aquaponic system i built, was still bulletproof after more than a year and a half. there's nothing to prove there: it works. in my opinion, there's no easier way to clone. no domes, no spraying, no hormones, no fuss. but, it had to go

i gutted the whole room to streamline my operation. no more cloning and veg for the time being. that should help out with getting heat and power consumption under control. reworked the ventilation so that my lights have a separate intake/exhaust from the room. also just upgraded the lights to dual fixtures, so i've got a 600watt HPS above each tray with 5 plants. at full power, that's 120watts per plant in a 9"x9" basket. at full capacity, that's 600watts/8 plants = 75watts per plant or 600watts/4.5 sqft = 133watts/sqft. right now both lamps are dialed down to 300watts each.

my new system is about 100 gallons and modeled after the University of Virgin Islands (UVI) system, which is one of the more popular ap system designs out there. i skipped the "bioball barrel" since my system has plenty of hydroton in it to provide surface area for the nitro bacteria. i also skipped the degassing barrel since there's plenty of aeration going in my lower res. i reused "dirty" parts and hydroton from the old two systems as bacteria cultures so i wouldn't have to cycle the new system.

my approach this time is to keep nute concentration relatively low in the 500-1000ppm range and to keep pH wandering between 5.5-7.0 or thereabouts. ideal pH for nitro bacteria is around 7-7.5 but nutrients start to precipitate out of solution at that point. i think they still do their thing down to pH of about 6.0, so i want to make sure i keep it going back and forth.

using citric acid seemed like a bad idea last season. i think it was killing my bennies and nitro bacteria, plus it couldn't hold pH worth shit. using 80% phosphoric acid and going with a res volume/plant ratio of about 10 gallons/plant. some claim it gunks stuff up, but i never saw that happen.

so far so good, with the exception of going overboard with the phosphoric acid. pH dipped way down to 3.2 and killed off some fish. those that survived the 4hr acid bath i know are resilient to low pH and can hang out at pH of 5.0 or higher all day. i found that the fastest way to bring the pH back up was to dump 5 gallons and refill with tap water (8.0+ pH, 250ppm).

clones came in rockwool blocks, which i buried in hydroton. algae seems to love rockwool and high pH but seems to have a hard time growing on hydroton, so i'm keeping the rockwool blocks completely covered with hydroton and the top inch or so of hydroton dry. i inoculated the rockwool blocks with great white directly before putting them into the system.

using tap water, phosphoric acid, calmag, CNS17, and eventually a bloom booster once things get going. feeding fish plain ol' goldfish food a few times a day. i might experiment with feeding them some chopped fruits and veggies eventually or adding a vermiponics bucket to the system.

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two 32-gallon heavy duty gargage cans. lower one is fish tank with mostly goldfish and some local minnow species of some sort. upper one is vortex filter with crawdaddy, pleco, snails.

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don't mind my mess on the floor. vortex filter drains to flood trays. the flood trays are connected, so there's only one autosiphon drain. autosiphon consists of 3/4" PVC drain pipe with 1-1/2" bushing to create the vortex, 3" PVC bell, and special "stealth" manifold underneath to keep it super quiet.

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day 4

**haole420** · 09-04-2012, 07:21 PM

currently, pH 5.6, EC 0.82, 596ppm

**haole420** · 09-06-2012, 07:37 AM

left out GH micro fro the list of nutes. also, three daily feedings of goldfish food seems to bump up EC by 0.01 every two days or so (~5ppm/day). planning to reduce fish feed to once every other day during flushing to minimize ammonia/nitrate/nitrite production. was also considering letting the pH rise to 7.5 during final flush in hopes of locking out nutrients but this might cause issues mineral precipitation. still a ways off, so i'll figure it out then. there are always those who say flushing doesn't matter and that it's all in the cure...

**haole420** · 09-06-2012, 07:39 AM

Originally Posted by corwinlame

grow light home depot

yes, "grow light home depot," as they say. sounds like a bot to me.

**berkman858** · 09-06-2012, 10:58 PM

Nice setup but are the fish in those res bottles? Seems like a shit life for the fish, not being able to swim around much at all. Not that I really care about fish... just my opinion.

**haole420** · 09-07-2012, 10:29 PM

Originally Posted by berkman858

Nice setup but are the fish in those res bottles? Seems like a shit life for the fish, not being able to swim around much at all. Not that I really care about fish... just my opinion.

they live in one of the 32gal garbage cans. plenty of room for them. they seem pretty content. most of the fish have been going for over a year, and previously in even more cramped conditions with crazy turbulence caused by bell siphon draining on top of them every 10 minutes 24x7. don't tell PETA!

submerged mini milk crates give them an area with a sense of security, plus there's leftover pieces of 1-1/2" PVC pipe and elbows in there that they hang out in. the wild minnows have even bred a few times, which is a sign of low stress and good environmental conditions. they end up eating most of their fry, but a few survive somehow.

**haole420** · 09-07-2012, 11:12 PM

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increased light to 2x 400watt HPS. going to hold steady there for a while. lots of new growth filling in. the solid state variable speed fan controllers made it possible to dial in the light cooling fan and room exhaust fan to exactly where i needed it maintain temp/RH. big improvement over the standard 3-step fan controls.

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inoculated with great white and a few days later with another (much cheaper) endomyco formula from gardening supply store. nice fuzzies on one, fishbones on another.

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the taller ones stretched about 4 inches in the first week. the 6 pulleys suspending the boom proved to make raising the two reflectors a breeze. that thing is rock solid. you could sit on it if you wanted to. big improvement over the old chains and s-hooks i was using. thinking of adding another two pulleys to each side to convert to double luff tackle and increase mechanical advantage from 3:1 to 5:1.

**haole420** · 09-14-2012, 12:28 AM

started with pH 5.2, went up to 5.4 - 5.5 once i started adding nutes, holding nice and steady.

not sure what's up with my hanna meter. i thought i was at 600-700ppm or so, but after recalibrating with hanna reference solutions, it was reading 1000-1100ppm. i think the probe or the test packets are bad, so i'm going to hold off adding any nutes until i get new probes, recalibrate, and figure out where i'm at. ec and ppm are stable though. feeding the fish gives the system a little bump, but by less than 0.01mS or 2ppm. plant uptake is just starting to outpace ammonia production by fish on a moderate feeding schedule.

i haven't flushed, nor do i intend to. res temp going between 25-27C (77-80F) night/day. while DO might be down, the roots get 100% air about 1/2 the time with the ebb/flow, so it really doesn't matter. root rot almost never happens in aquaponics, by the way. i haven't added any H2O2 or bennies (except for initial root inoculation with great white). the whole point of this approach is to take as much of the hassle and risk out of hydro. i'm after an environmentally friendly, quasi-natural approach that's tolerant to non-sterile conditions, lots of organic debris in the system, high temps, low DO, and a slacker grower that doesn't want to flush my system every week.

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9 are silver haze, 1 is great white shark (orange ziptie around base). these are the taller 4 silver clones.
the taller silvers have been showing obvious pistils since day 7, but they seem more focused on bushing out whereas there are noticeably more pistils on the shorter silvers below (all from the same mother).

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front-left is the great white along with the 5 smaller silvers. one is still tiny. it was the smallest one to begin with. showing some growth in the past few days, but it took a while. i think it was waterlogged in the rockwool. now that the roots have made it out of the block and into the hydroton, it's darkening up and growing.

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recovering leaf from great white. the great white was the one that seemed to show deficiency the fastest, but it also seemed to recover the fastest once the roots made it out of the rockwool. chlorosis of the lowest/oldest leaf or two on the silvers seemed to set in more slowly, but only half of the leaves recovered. some dried up, some are still all yellow but alive, and some are greening up again. the great white (more indica) definitely has the faster metabolism. it seems to be flowering the faster.

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topped the tallest silver and stuck it in some hydroton 2 days ago. no cloning gel, no dome, no misting, no rockwool, just constant ebb/flow in 1000ppm of nutes and fish poop. not exactly how most people clone. as soon as it roots, i'm going to veg it out under some HO T5s in another room. considering hempy. hopefully i can pull a dozen clones off of it when these are finished. i never tried rooting under 11hrs light, but i'm sure it'll be fine. the transition to full on veg might be slow, but as long as it roots it'll be fine (i hope).

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roots starting to emerge from baskets. they got pretty long last time. there's a steady current through the tray with the drain in it, but it's a little slower through the second "slave" tray. a lot of fine particles of uneaten food that made it through the vortex filter end up settling in the second tray. i added a few feeder minnows to both trays to eat up the settled food (fine, powdery, clumps) and covert it to heavier, well-formed poop which doesn't foul the roots as much. i also added two crabs to the second tray who are just going to town cleaning up. i've seen both the fish and crabs grooming the roots. roots are snow white and smell like sprouts, even with all that organic material floating around. i don't care if they chomp on the roots. think of it as pruning. a little trauma should cause the roots to branch.

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heavily darwinized population of goldfish, bluegill, and wild minnow. some of them have been going for 2 years in some really ridiculous conditions. out of about 200 fish over two years, these are the 30 or so badasses that survived. NH3/NH4+ are ~4ppm, which is considered somewhat high for freshwater aquariums. pH below 7 is definitely slowing down the nitro bacteria, but it's been steady at around 4ppm and looks like it might be coming down slightly, despite constant overfeeding. we'll see if the scavengers have any impact.

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both lamps at 600watt now. for fan speed control, the solid state controllers are the way to go. they control voltage and frequency, so you can dial it down to any speed and there's never any hum or heat. beats the step controls, which seem like they only give you fast, really slow, and super slow speed presets. the shorter bunch was under 400watts for a few more days before getting bumped up to 600watts. they were also further away, so maybe less intense light kicked them into flowering more? as you can see, i offset one of the reflectors to be right on top of the shorties.

over the next week, i'm going to push the pH up to 6.0 to cover the upper pH range for nutrient absorption. i'll eventually push it back down to 5.2. i've ruled out going as high as 7.0-7.5, which is the optimal range for the nitro bacteria. i don't think i'll go beyond 6.0, at which point calcium phosphate starts to precipiate out of solution, encrusting roots (and everything else) with hard scale. this is what killed my grow in week 7 or 8 last time.

**haole420** · 09-21-2012, 01:34 AM

Day 20:

everything looks stable except for the fact that the sump pump went dry twice, added 15 gallons tap water this week (~100 gallon system). the sump needs a float valve hooked up to water res to top off automatically.

still haven't flushed in three weeks. it's truly a recirculating system. water temp 26-27C. no H2O2, no bennies, no root rot, just naturally occurring probiotics.

1200ppm/1.64ms yesterday, when the sump went "dry" (less than 4") for the second time this week. after adding 10 gallons, brought it down to 1129ppm/1.54ms with slight upward effect on pH, 5.2 to 5.3. i think the real ppm/ec is somewhere south of these numbers. not planning to add any nutes until i get back down to 700ppm or so and my new meter probe arrives.

pushed pH up to 6.0, but growth seemed to slow at anything about 5.5, so brought it back to 5.2-5.4 and things seem happier.

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i upgraded to double pulleys so now at 5:1 mechanical advantage on each side, you can raise/lower the ~70lb boom/reflector assembly with two fingers using hardly any force (~7lbs on each side). i considered splitting the boom in half so i can adjust height of each reflector separately, but adding a few lengths of chain was simpler. maybe after this grow.

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taller silver hazes continuing to stretch, maybe at about 2ft now. a little slower than the great white for pistils to emerge, but things looking on track so far. roots just hanging out without any kind of shroud.

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stumpier ones still stumpy, but growing. should do better now that the light is right on top of them. the great white (front/left) is at least a week ahead of the silver hazes. edge leaf curl seems to appear when i don't refill the humidifier regularly.

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saw some kind of larvae under a few leaves, so sprayed everything down with a harsh knockdown spray for roses/shrubs. luckily, i tested it on this plant first. fail. all but one branch wilted, died, and eventually got chopped. roots still looked great, no rot or fouling. switched to an organic spray for fruit/veggies for the rest of them. sprayed every leaf individually, then wiped each leaf with paper towel soaked in spray a few days later. no sign of larvae, whiteflies, or any other critters so far.

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clipping still going strong after about 10 days. still hasn't rooted, but it's getting bumpy down there. veins turning dark green and showing new growth. that whole thing about clippings not being able to uptake nutrients until it sprouts roots? that's bullshit. i can't say whether this is unique to aquaponics or not, but this clipping is definitely sucking up nutes, sans roots. not one leaf has fallen off of it, and it's just continuing to flower. interesting to see how it will finish.

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crabs, mini catfish, feeder fish doing an awesome job cleaning up roots and trays. i don't feed them, so they pretty much have to scavenge for food. flood trays are totally free of fine food particles that used to settle in the troughs, especially in the slave tray that fills/drains hydrostatically and lacks a current fast enough to move the debris. saw one of the crabs chomping on some emerging roots. it mowed down about 7 root tips. a few days later, another 20 or 30 root tips poked through. i don't think the crab pruning hurts, i think it actually stimulates branching within the basket. hopefully i won't end up with a tangled 2ft coiled beard under every plant like i did in DWC bubble buckets.

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fish bulking up nicely. installed automatic fish feeder and set timer for dawn/dusk. fine particles of fish food settled all over vortex filter before. pleco and crawdaddy doing excellent work keeping it spotless. i usually keep it covered 24x7 since the pleco is a nocturnal feeder.