Update to my IBC system

[Mike Beckman]

 Plants are doing amazing.  Peas growing all over the rafters, squash growing over the media bed, down to the floor, tomatoes tied up to the rafter and flowers everywhere however, fruit production has been extremely poor.  3 tomatoes, one huge cucumber, several smaller squash not growing very much, the chiltepin peppers have lots growing but thats about it.  I added a 50% shade cloth, exhaust and input fan at opposite ends of the greenhouse.  Water is staying in the low 80's.  Fish seem to be more or less active depending on the PH.  About 12 died in April and May, lost only one since and they are growing.  I shake the tomato plants for pollination but shaking all the plants doesnt seem to be doing anything so I am thrilled with the plants but disappointed in the production.  Adding about 10 gallons of water a day due to evaporation, filling two 5 gallon pails in the morning and then putting that water in the tank the next morning.  

Any recommendations to increase the production?  Is hand pollination the only way and is it different for each type of plant?  Thanks to all for your help.  

Mike

[Jeff S]

A fan blowing across the plants should facilitate pollination. Maybe an oscillating fan.

[Mike Beckman]

Hi Jeff, thats the type of fan I put in and use every day.  I can raise the position of the air stream and see if that helps.  Right now its hitting just above the media bed.  Thanks for the suggestion.  

[Arthur King, Jr.]

Hi MIke,

I have similar issues with my tomatoes.  I added a fan which did seem to help some as well as was shaking the plants daily.  Huge plants but not a lot of fruit.  Mine may be temp as my water is only 70 Degrees F.

I am pretty sure squash have make and female blows so they will need hand pollinated.

Art

[Leo White Bear]

Mike

  All of the suggestions are great but none addressed the problem.  I would do as these people suggested but add one more.  Because tomatoes are actually hybridized from weeds they have the tendency to follow this pattered.  Check your nitrate levels.  With a surplus of nitrogen in the water, you will experience a lot of green growth but little fruit.  By raising the potassium, magnesium and calcium levels the plants should start to set fruit.  As a master gardener, I get this question quite often and soil gardeners are at their wits end.  Transfer this to apply to aquaponics and you will experience good fruit production.  All your other vegetables will also benefit from this augmentation.

  Squash and cucumbers have male and female flowers.  Look at the base of each flower for an enlarged area that looks a lot like miniature fruit or enlargement.  Those that have this are the females those that don't, are males.  Being in an enclosure, you will need to hand pollinate the female flowers.  Pinch off a male flower and, if you don't intend to cook the flowers for dinner, pull off the petals down to the pollen ladened stamen.  Push back the petals of the female flower GENTLY as to do no damage and touch the male to the female overie.  You can use this male several times to pollinate multiple females.  Release the petals and you will see that they will curl into themselves letting you know that they have been pollinated.  If they do not curl back onto themselves, you may need to pollinate them later.  This curl should become evident within the next few hours.

[Mike Beckman]

Thanks for the replies.  I re positioned the fan and will continue shaking.  Leo White Bear - I tested the water this morning.  Ph - 6.8, Am-.25, Ni and Ni both 0.  Will get a new test kit ordered since the one I have is at least 6 months old and has been in the heat for a while so numbers may not be accurate.  If I need to raise the potassium, magnesium and calcium levels, what is the best way to do that?  The squash flowers are as you describe, will try the hand pollination today and will check the cucumber flowers and see if I can spot the difference.  Everyones help is much appreciated.  This is an experiment to see if I can get through the summer heat and be productive before expanding from a single grow bed.  

[Leo White Bear]

Mike-

  Adding various nutrients to aquaponics is slightly difficult.  I say this not to scare you off in doing so but to remind you to be cautious.  Potassium and calcium are the easiest to add as they can be added at the same time by adding potassium carbonate or bicarbonate and can be found in beer brewing supply stores.  Magnesium is a little touchier.  You can use "Magnesium Sulfate" otherwise known as Epsom salt.  As the name implys this is a sodium product.  Some salt is good for freshwater fish but don't go overboard with it.  Little is better than more.  In a system such as yours, 1/2-teaspoon leveled is enough.  This must be treated as a MICRO-NUTRIENT.  Check out your cucumbers and you may need to hand pollinate these also.  Welcome to my world, I use to grow barrel gourds in soil.  I would have to go out at night and hand pollinate just under an acre in the late spring to get any fruit. 

Mike Beckman said:

Thanks for the replies.  I re positioned the fan and will continue shaking.  Leo White Bear - I tested the water this morning.  Ph - 6.8, Am-.25, Ni and Ni both 0.  Will get a new test kit ordered since the one I have is at least 6 months old and has been in the heat for a while so numbers may not be accurate.  If I need to raise the potassium, magnesium and calcium levels, what is the best way to do that?  The squash flowers are as you describe, will try the hand pollination today and will check the cucumber flowers and see if I can spot the difference.  Everyones help is much appreciated.  This is an experiment to see if I can get through the summer heat and be productive before expanding from a single grow bed.  

[Jeff S]

I use the recommendation from Bright Agrotech. Every other week I put in 3 tbsp. Epsom Salt, 3 tbsp. potassium sulphate, 6 tsp. iron chelate into my 500 gallon system. Everything looks real healthy. Before I started doing that the plants didn't look as good. If I need to raise pH I substitute the potassium sulphate with potassium hydroxide and sometimes hydrated lime (garden lime). Carbonates work just as well but create a buffer, which is good for the most part, but the buffer makes accurate quick changes to things like pH a little more difficult for folks like me who don't do measurements every couple of days. If you haven't found the Bright Agrotech videos I suggest you take a look at them. Everything you need to know about aquaponic nutrients in short accurate videos.

[Mike Beckman]

Thank you Jeff and Leo White Bear.  I have been using Potassium bicarbonate(suggested by Vlad early on) to bring my PH up and I added a teaspoon yesterday for PH and the additions suggested above.  Will get some epsom salts today and do the same.  I am adding the micro-nutrients to the grow bed right under the water input from the fish tank.  Is it better to add it to the water directly?  Will also try the hand pollination suggestions today and glad I dont have an acre to do!!  Wow.  Jeff, thank you for the Bright Agrotech recommendation, will find and view them asap.  Also will let you know how I make out and once again, thank you for both of your interest and advice.  Much appreciated.  

[Jeff S]

If you have a sump that's the best place to add nutrients. If not just put them in a jar of water to dissolve them. Not sure what adding direct to the bed will do as far as bacteria and we know you don't screw them up.