Backyard Aquaponics
A place to discuss aquaponics

I'm starting to wonder if my lettuce not heading up really dense is more to do with nutrient balance now rather than light since yours appears to be quite dense even under plastic and with some part day dappled shade of the tomato plants over head even after the past few weeks with some rather cloudy days for here this time of year.

What ppm are you running your nitrates at?

I've had nitrates at very different levels in different systems and still seen the somewhat loose heads forming. That is why I mention nutrient balance rather than nitrate levels as being a probable culprit.
Intense sun coupled with cooler temperatures and dryer weather tends to form more compact heads in my experience but I've never managed to get that growing my lettuce out under plastic since it filters so much of the UV light. But I see nice deep reds and compact heads in Ryan's system despite being inside a greenhouse and getting some shade from tomato plants overhead.

I think right now my Big raft system is a little low on Nitrate but I've grow lettuce when the nitrates were really high and still had similar results so I suspect it is more complex than simply the nitrate levels.

hey Ryan...

I am new to Ap and have set up a small unit at my house. All thanks to your informative posts and picture, otherwise i wouldn't have come this far.

So far i have 6kgs of catfish in a 500ltrs tank, a 400ltrs sump to push the water to the grow bed and in between the exact replica of filters you had. 3 tanks tied together, first one got baffle in it, the second one has bio balls and the third has net in it. With 8(200ltrs) half split blue pvc barrels as grow bed. 5 of them has gravel in it and the rest 3 i use with raft in it.

Which filter system you think works the best? Swirl filter or a clarifier?

Its been over a month since I planted lettuce tomatoes strawberries and spinach and their growth seems poor to me. you think if I add more fish would that help? what should be the idle stocking density because i am planning to add another 1000ltr fish tank to the system and a few raft barrels to it.

If I manage to keep the nutrient filled water cold enough in summers for lettuce to grow, will that work without the plant bolting?

Cheers

I generally test around harvest time or sample before harvest to check levels (same as you would check grapes in a vineyard before harvesting everything to process into wine).

How long after changing feeding is it noticeable? No clue I try to start and end with a healthy productive plant, I'm not having to overcome deficiencies much these days.

Does pH affect it? Sure, it does. How much depends on the species of plant.

Too high? Not that I've seen.

Vegetive vs fruiting stage? They will differ. Test lettuce when it's ready to harvest and again when it has gone to seed... Big difference. I don't usually test leaves of fruiting plants though... We are testing the fruit.

No good articles, sorry.

Thanks bud! They do need an extremely low pH so I grow mine in pots that have an acidic media and water with AP water. You could probably grow them in a media bed if you surrounded the rootball with coffe grounds/pine bark and gave it additional top dressings of coffe grounds from time to time. I'm going to try it in a few months so I'll let you know!

Thanks Charlie!

Fister-
1)it's suitable if the system is designed correctly
2)Sorry but I consider this proprietary
3) It really depends on what I am growing. I've grown in the range of 5-150.

Damian- no, I bought these all as individual seed packs from a few different companies. They are all delicious though!

I guess that answers my question as to whether or not I can grow celery in dwc. Impressive Ryan. Do you use sticky traps in your greenhouse at all? If so, so you use them just to monitor? I'm concerned about using them and catching too many beneficials as well as pests. Figured you would know, since you use solely predatory "bugs" for pest control. Do you buy your own fish food or make it? Trying to pick a brand and can't decide which is best for AP. Do any have formulations for plants? ie, more Ca, Fe, Mg, etc?
PS- just looked at pic again..not celery. fennel?? So many different plants that I don't know.lol Ask me about woody ornaments...I can ID 90%. But am clueless on most veggies and herbs once you get away from what is at Publix.

Thanks Ryan. You're a wealth of knowledge! I'll have to give it a go!

And that sliced tomato looks delicious! What type is it?

Beautiful pictures, so nice!

Those sliced tomatoes are making me hungry

Celery actually grows really well in Rafts or media beds, heck even towers though growing it in towers kinda affects the marketability of the stalks.

About How long did that Fennel Take Ryan? Looks nice!

I am truely a fan of your work, I sure hope we could do some work together someday. I have to ask some more questions that are burning my mind.

When you post pics of produce is that the pick of the day? If so what's your total volume of water your working with and daily feed amount, you seam very productive from my estimate of your floor space,(sorry if i missed it earlier in the tread). Is that a normal picnic size disposable plate, you know the one in the pic that is covered by only 4 slices of beefstake.

Interesting comment on being able to provide a PH spifick root zone for a single plant in a AP grow bed.

Brix comment up for discusstion/corection.
I personally compear brix of plants to blood suger testers and diabetics. I am thinking that you should be testing ever 3<10 days, the brix is a messurment of sugers in the plant sap and therefore how active the plant is, it takes 3<10 days for a plant to correct it self of a micro defishentcy, when the nutrent is applied foilarly, so i believe a plants internel mecanisum works in that time frame. I could be wrong but I believe the brix level during early growth is just as important as final brix or even more so because as you said strong starts equal good saleable product. Lets use the tomatoes as example the ones in the tom only system should maintain a brix higher than the ones in the mix system,because the growth is better. Then you should be getting a different reading in brix 3<10 days after you add your propiortery efulent. Enableing you to fine tune your mix by the resulent rise or fall in brix.

Your going to be triming back new shoots from the plants often anyways that's the best place to take the sap from.

TCL, I am also VERY curious on what makes lettuce grow a dense head. Sometimes I can get it nice and dense and other times not.