Managing pH in Earthtainer

Winemaker · May 24, 2016

Last year I had a lot of BER in my tomatoes even though I know I had plenty of calcium in the Earthtainer. Doing some additional reading I found articles indicating ideal pH for tomatoes was 6-6.8 and when it was higher that Calcium uptake by the plant was diminished. I measured the pH of my tap water and it is consistently 7.5. I have an inexpensive soil pH and moisture meter and it also indicates the Earthtainers are at 7.5 pH.
I use an inline EZ Flow unit and am adding some Aluminum Sulfate to the EZ Flow but wondered how others are managing pH in Earthtainers. I don't want to overshoot on this and unsure how quickly the Aluminum Sulfate will lower the pH in the ET. I have used Aluminum Sulfate in the past to get my Hydrangeas nice and blue but that was always sprinkling it on the surface and watering it in. The pH on my Blue Hydrangea in a large container is at 5.5.

AKmark · May 24, 2016

I think liquid Phosphoric acid will help, it goes right in your mix. I use alot of it, but do have a different set up, which should not matter

rnewste · May 24, 2016

winemaker,

When I reuse the potting mix from the previous year, I see less BER versus Tomato plants in brand new mix. Perhaps the Dolomite Lime from previous Seasons had had time to assimilate into the older potting mix and stabilize.

In any event, I would be wary of cheap pH meters - they simply are measuring electrical resistance (conductance) and translating the indicator to an arbitrary pH scale readout, which is suspect to accuracy. A comprehensive soil analysis is best.

Raybo

Winemaker · May 24, 2016

The soil pH meter is clearly suspect. When it read the same as the water pH I figured it was probably close to correct.
As to the water pH, I am sure on that one.
As a winemaker, my liquid pH meter is very accurate, but it is of no use when it comes to checking soil pH.
So far no indication of BER on my tomatoes but I am also not growing any Romas this year which are always the ones with the most BER problems. Big Beef, Better Boy and a couple Red Cherry types.
Clearly the Hydroponic guys are very sensitive to pH and much easier to monitor and adjust. Soil and growing mix have a certain amount of buffering that they do and as a result, moving pH is more difficult.
I guess at this point a wait and see approach is probably the best idea.

BajaMitch · May 25, 2016

You might try a quick fix using white table vinegar (5% acidity). All last year I had a problem with high pH and cured it with periodic use of vinegar. I use a solution of 1 tablespoon of vinegar (5% acidity) to 3 quarts of water and feed a 6 gallon container with 1 quart of this liquid solution (top watering), wait a day, then measure the pH to see if I need more to bring the pH reading down to 6.5 approximately. When using vinegar, monitor the pH daily to determine how much of the solution is necessary to keep the mix in the proper pH range. Take readings at different levels of the mix, that is, measure the pH at 2 inches below the surface and at 8 inches below the surface...keep good records.

May 24, 2016	#1
Winemaker Tomatovillian™ Join Date: Apr 2012 Location: El Dorado Hills, Ca Posts: 47	Managing pH in Earthtainer Last year I had a lot of BER in my tomatoes even though I know I had plenty of calcium in the Earthtainer. Doing some additional reading I found articles indicating ideal pH for tomatoes was 6-6.8 and when it was higher that Calcium uptake by the plant was diminished. I measured the pH of my tap water and it is consistently 7.5. I have an inexpensive soil pH and moisture meter and it also indicates the Earthtainers are at 7.5 pH. I use an inline EZ Flow unit and am adding some Aluminum Sulfate to the EZ Flow but wondered how others are managing pH in Earthtainers. I don't want to overshoot on this and unsure how quickly the Aluminum Sulfate will lower the pH in the ET. I have used Aluminum Sulfate in the past to get my Hydrangeas nice and blue but that was always sprinkling it on the surface and watering it in. The pH on my Blue Hydrangea in a large container is at 5.5.

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May 24, 2016	#2
AKmark Tomatovillian™ Join Date: Jun 2013 Location: Wasilla Alaska Posts: 2,010	I think liquid Phosphoric acid will help, it goes right in your mix. I use alot of it, but do have a different set up, which should not matter

May 24, 2016	#3
rnewste Tomatovillian™ Join Date: Apr 2007 Location: Campbell, CA Posts: 4,064	winemaker, When I reuse the potting mix from the previous year, I see less BER versus Tomato plants in brand new mix. Perhaps the Dolomite Lime from previous Seasons had had time to assimilate into the older potting mix and stabilize. In any event, I would be wary of cheap pH meters - they simply are measuring electrical resistance (conductance) and translating the indicator to an arbitrary pH scale readout, which is suspect to accuracy. A comprehensive soil analysis is best. Raybo

May 25, 2016	#5
BajaMitch Tomatovillian™ Join Date: Sep 2015 Location: California Posts: 84	You might try a quick fix using white table vinegar (5% acidity). All last year I had a problem with high pH and cured it with periodic use of vinegar. I use a solution of 1 tablespoon of vinegar (5% acidity) to 3 quarts of water and feed a 6 gallon container with 1 quart of this liquid solution (top watering), wait a day, then measure the pH to see if I need more to bring the pH reading down to 6.5 approximately. When using vinegar, monitor the pH daily to determine how much of the solution is necessary to keep the mix in the proper pH range. Take readings at different levels of the mix, that is, measure the pH at 2 inches below the surface and at 8 inches below the surface...keep good records.