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?

 

[RupertofOZ]

Yes they will buffer pH Stephen, and quite markedly.... so use sparingly...

Potassium Chloride will certainly provide a potassium boost... but will also raise the salinity... so likewise, use sparingly...

Maxicrop seaweed extract, and/or burying a banana will also provide potassium... albeit in smaller amounts...
 
Stephen Eugene Robinson said:

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]

By pH buffering, I mean the capacity of a tank to resist changes in pH.  Potassium Hydroxide and Calcium Hydroxide are very alkaline.  Using these chemicals would seem to cause rapid shifts upward in pH.  I use a buffering agent that attempts to hold pH to 7.0 and usually does a good job.  My tank has been going since March, about 8 months.  Left to its own devices it tends to pH of about 6.3.  I use this buffering agent whose chemical composition I don't recall, but that I got in an aquarium store to buffer pH swings.  I also use some old reef tank base rock (mostly calcium carbonate) to slowly raise pH to resist the trend downward.  Seems to work.  I add a little of the buffer compound (maybe 20g) every couple weeks and the pH stays at 7.

The calcium carbonate should provide calcium to the tank as it slowly disolves, not sure at what rate.  I may take out one of those rocks and replace

[Stephen Eugene Robinson]

(seem to have chopped off some of the text of the message)  and replace it with KOH.  I am not sure how much to use.  Do you have a suggestion for a 170 gal tank supporting 23 square feet of growbed raising mostly squash, tomato, and pepper?
 
Stephen Eugene Robinson said:

By pH buffering, I mean the capacity of a tank to resist changes in pH.  Potassium Hydroxide and Calcium Hydroxide are very alkaline.  Using these chemicals would seem to cause rapid shifts upward in pH.  I use a buffering agent that attempts to hold pH to 7.0 and usually does a good job.  My tank has been going since March, about 8 months.  Left to its own devices it tends to pH of about 6.3.  I use this buffering agent whose chemical composition I don't recall, but that I got in an aquarium store to buffer pH swings.  I also use some old reef tank base rock (mostly calcium carbonate) to slowly raise pH to resist the trend downward.  Seems to work.  I add a little of the buffer compound (maybe 20g) every couple weeks and the pH stays at 7.

The calcium carbonate should provide calcium to the tank as it slowly disolves, not sure at what rate.  I may take out one of those rocks and replace

[RupertofOZ]

The use of Calcium Hydroxide, or Potassium Hydroxide... both very powerful pH buffers... is generally to address pH levels that have dropped <6.2 ... and need to be brought back...

The best self, and probably safest self regulating pH buffer... is Calcium Carbonate.... the coral rocks will certainly provide that, but due to the fact that they're very hard structures, may not dissolve the carbonate buffer fast enough to counter the acidification of nitrification in AP systems... although usually they do...

Try adding shellgrit into your grow beds, or in a sock under a water inlet/outlet.... it will self regulate the pH... (until exhausted)...

 

If you need to use the Potassium, or Calcium Hydroxide... then use sparingly... as you don't want to move the pH too fast for the sake of the fish....

A teaspoon in 170 gallons should be sufficient....

A pH of 6.2-6.4 is actually probably the optimum for AP systems, and plant growth... and it would be extremely unlikely to suffer any trace element deficiency problems within that pH range...

I'd suggest your problems probably are more related to lighting, than any deficiency problems... and buffering with some Potassium will certainly help both your flower set and pH...

Remember though... that blue light, and nitrogen... is preferred for early plant vegetative growth... but red/violet light, and trace elements are more necessary for flower/sed/fruit set...

 

Many senior members run their AP systems constantly between pH values <6.6 ... often down to about 5.8.... as do all hydroponic systems...

But below 5.8 ... the pH will begin to inhibit the nitrifying bacteria...

Also, the nitrification process needs provision of Calcium... as does plant growth... hence the suggestion that Calcium & Potassium buffers should be alternated...

 

P.S ... my systems often run at a pH of 6.0 or less... before I actually get around to buffering them...

P.P.S... chuck the bottle of the pH Up away... and cross the street and walk on the other side of the road from the aquaria shop... and promise never to go inside there again...

[Stephen Eugene Robinson]

Thanks

 
RupertofOZ said:

The use of Calcium Hydroxide, or Potassium Hydroxide... both very powerful pH buffers... is generally to address pH levels that have dropped <6.2 ... and need to be brought back...

The best self, and probably safest self regulating pH buffer... is Calcium Carbonate.... the coral rocks will certainly provide that, but due to the fact that they're very hard structures, may not dissolve the carbonate buffer fast enough to counter the acidification of nitrification in AP systems... although usually they do...

Try adding shellgrit into your grow beds, or in a sock under a water inlet/outlet.... it will self regulate the pH... (until exhausted)...

 

If you need to use the Potassium, or Calcium Hydroxide... then use sparingly... as you don't want to move the pH too fast for the sake of the fish....

A teaspoon in 170 gallons should be sufficient....

A pH of 6.2-6.4 is actually probably the optimum for AP systems, and plant growth... and it would be extremely unlikely to suffer any trace element deficiency problems within that pH range...

I'd suggest your problems probably are more related to lighting, than any deficiency problems... and buffering with some Potassium will certainly help both your flower set and pH...

Remember though... that blue light, and nitrogen... is preferred for early plant vegetative growth... but red/violet light, and trace elements are more necessary for flower/sed/fruit set...

 

Many senior members run their AP systems constantly between pH values <6.6 ... often down to about 5.8.... as do all hydroponic systems...

But below 5.8 ... the pH will begin to inhibit the nitrifying bacteria...

Also, the nitrification process needs provision of Calcium... as does plant growth... hence the suggestion that Calcium & Potassium buffers should be alternated...

 

P.S ... my systems often run at a pH of 6.0 or less... before I actually get around to buffering them...

P.P.S... chuck the bottle of the pH Up away... and cross the street and walk on the other side of the road from the aquaria shop... and promise never to go inside there again...

[TCLynx]

I have been using potassium bicarbonate (I buy it from wine and brewing supply places) and calcium carbonate (my well water has plenty or I can use shell grit like you give to chickens or garden lime) as my buffers