[Higher Thinking]

So I have a nice little garden box going with seven tomato plants. Before I did any research I probably made the initial error of over fertilizing. I was using water from my tank that I dose EI because it seemed that would be the best water being that it is saturated with nutrients. Well the plants definitely took off, but then I started doing some more research. Turns out tomatoes don't need high nitrogen and dosing as such will result in beautifully lush green plants, but no tomatoes.

I stopped dosing and just resumed watering which I learned would flush the excess nitrates from the soil and have since seen over ten tomatoes growing now. I went ahead and did the trimming of all the branches below where the plant was flowering as I learned would better induce fruiting.

Now my question is can I still somehow dose any of my dry ferts such as potassium and phosphate? I read that once you start getting fruit you should fertilize once again. So is there anything I can do apart from getting actual tomato fertilizer? Does anyone have experience using our normal dry ferts in their gardens? Please leave some insight, thanks!

Box is 8'X2'X1' and has about 12 cubic feet of soil which somehow nearly fills this box which is 16 cubic feet.

 

[Sharkfood]

Too much nitrogen can result in more plant growth with less fruit, but hydroponic mixes for tomatoes have a lot more nitrogen in them than an EI dosed tank. If the box drains well, you can flush the mineral salts by running water through it for some time.

I've always fertilized tomatoes grown outdoors with general purpose fertilizer, and there's always more tomatoes than I could ever use.

I've only ever mixed hydroponic fertilizers with dry salts, and in those cases I just clone whatever bottle of general purpose hydroponic nutrient I have laying around.

If I'm growing something like lettuce, I just dilute the reservoir to 1/2 or 1/4 strength.

 

[FishFarmer]

Honestly, if I were you I would not fertilize again. It sounds to me like you have a very nutrient rich soil there, between the aquarium water irrigation and judging by the dark color of that soil, it is very high on organic matter and thus most likely full of nutrients. If you do want to fertilize at all, you can maybe do a little potassium as that will help the plant translocate sugars and other compounds into the fruit. You can also do a foliar application of boron (be sure to apply the correct amounts and not too much, because it can be toxic at high concentrations). Many farmers, especially on soybeans, tomatoes, and peppers do a foliar application of boron upon fruit set, which really does help the plant bear more fruit.

And you are right about the high N rates; high N rates promote vegetative growth and delay the set of flowers--this is especially prevalent in the solanaceous crops (tomatoes, peppers, potatoes, etc...); although I don't really think there is enough N in your aquarium water to reduce your yield, so I'd say you could probably still water with that, maybe a bit less frequent now that the plant is fruiting.

Hope that helps you out some. I am an agriculture major, so this is right up my ally :icon_smil