Tomatos slow to blossum

[Stephen Eugene Robinson]

The tomatos emerged from seed on Aug 15, and I have been expecting blossums for a while now.  I have three plants, lots and lots of green, and only two or three blossums.  Is something wrong? or am I just impatient?

 

[TCLynx]

Where are these plants?  Do they get enough sun?  What are the temperatures (tomatoes often don't produce blooms if the temperatures are too hot or too cold)?  Have you ever added any seaweed extract or supplemented with any sort of potassium supplement?  Often times potassium is the limiting element for flowering and fruiting in aquaponics unlike in hydroponics where phosphorus is needed.

[Chris Smith]

All the tomatoes that I have grown have taken several months to produce fruit. It is important to have plenty of calcium for the flowers. Without enough calcium the flowers will drop off even if they get fertilized. I prefer to use calcium carbonate as a pH buffer which keeps the calcium levels up. Have you had flowers dropping off?

These plants were started in sometime in August.

[Stephen Eugene Robinson]

I have the plants under 600 watts of first Metal Halide, then HPS.  I ran the lights for 18 hours/day.  I dose with epsom salts for magnesium, potassium, and iron.  I found out tonight that tomatos won't flower unless the day/night ration is about even.  I changed this ratio tonight.  I will continue dosing with potassium.  Do you know how much to add?  I have a bottle of something called no-salt, which is potassium cloride.  I got it in the grocery store.  My system is small, 23 cubic feet of tank, 23 square feet of grow bed.  I use dead marine coral chunks to help with pH control.  This should help with the calcium needs of the tomatos I would think.

 

Having said all this, it is just what I am doing.  Don't know if it is right.

 

By he way, my nitrates are running around 200.

 
TCLynx said:

Where are these plants?  Do they get enough sun?  What are the temperatures (tomatoes often don't produce blooms if the temperatures are too hot or too cold)?  Have you ever added any seaweed extract or supplemented with any sort of potassium supplement?  Often times potassium is the limiting element for flowering and fruiting in aquaponics unlike in hydroponics where phosphorus is needed.

[TCLynx]

I expect that if you get the light/dark cycles right you will see blooms soon then.  Also, tomatoes like a certain temperature variation between day and night for best bloom and fruit set.  I don't know the recommendation but you can look it up if you know to search for it.

[Stephen Eugene Robinson]

Being in my basement, when the lights are on, the room goes to maybe 76 degrees.  When the lights go out, temps drop to the 60's.  I would think that would be good for tomatos.

 
TCLynx said:

I expect that if you get the light/dark cycles right you will see blooms soon then.  Also, tomatoes like a certain temperature variation between day and night for best bloom and fruit set.  I don't know the recommendation but you can look it up if you know to search for it.

[TCLynx]

Yep I expect so too.

[RupertofOZ]

Your nitrates are high... promoting lots of leafy growth... light and temperature may also be factors...

Also make sure you pinch out any "lateral" spurs that appear... and trim all leaves below the flowers...

Add some potassium to boost flower/seed/fruit growth...

[Stephen Eugene Robinson]

I put in 100g of Potassium Cloride yesterday.  Hopefully his will do the trick. 

[Stephen Eugene Robinson]

I am interested in using Potassium hydroxide and Calcium hydroxide for the reasons you indicate, but these seem to be strong alkaline chemicals.  Do they also buffer the pH?
 
RupertofOZ said:

Your nitrates are high... promoting lots of leafy growth... light and temperature may also be factors...

Also make sure you pinch out any "lateral" spurs that appear... and trim all leaves below the flowers...

Add some potassium to boost flower/seed/fruit growth...

[Stephen Eugene Robinson]

One of the problems I had that seems to have been solved was that my plants would put out new growth, but the older leaves would die back.  The plants all looked spindley, and the nitrates were high.  I came to the conclusion I had a nutrient deficiency.  I added Chelated Iron, Potassium, and Magnesium in the form of Epsom Salts.  The effect was almost instant lush.  I was running my grow lights (HPS) 18 hours/day 600W over a 3x4' bed.  Also the nitrogen level seemed to improve.  From this, I assumed that the nutrient uptake in the plants had improved.  Unfortunately, I have no good way of measuring anything except Nitrate.  I have read than an EC meter helps, but I am not sure how.  I cut back my lights to 12/12 a couple days ago to promote blooming.

 

My tank is 170 gallons, I have 27 fish in the 8-10" range, and have the first lush grow bed 3x4, a second doing well 2x2, and a new third bed 2x4.  The other beds are under high intensity florescent lighting.

 

I am looking for tomato blooms in the first grow bed under the HPS lighting.  I am already getting peppers, though the plants are small. 

 

 
RupertofOZ said:

Your nitrates are high... promoting lots of leafy growth... light and temperature may also be factors...

Also make sure you pinch out any "lateral" spurs that appear... and trim all leaves below the flowers...

Add some potassium to boost flower/seed/fruit growth...

[TCLynx]

Now you might just apply a bit of patience and see what happens over the next week.

[Stephen Eugene Robinson]

Yeah, that might be what is needed now..
 
TCLynx said:

Now you might just apply a bit of patience and see what happens over the next week.