Seasoned growers know the importance of pH when it comes to achieving a successful harvest. If pH swings too high, nutrients like iron, manganese, copper, zinc and boron become less available to the plants. Meanwhile, a low pH can hinder the absorption of phosphorus, calcium and magnesium. Hydroponic growers particularly know all too well that when growing without the natural buffers of soil, pH becomes significantly more sensitive and susceptible to fluctuation. For many hydro growers, checking pH and adding chemical buffers becomes the most time-consuming aspect of maintaining their cultivation, as a significant fluctuation gone uncorrected can inhibit nutrient absorption, diminish plant health, decrease yields, and in extreme cases, lead to plant death.

Using up/down chemicals to moderate pH has typically been the industry standard solution, but this method has its setbacks. For hobbyist growers, this means excessive time spent constantly monitoring and dosing their growth. For commercial growers, this means the cost and complexity of setting up and maintaining automatic chemical-dosing systems.

A hydroponic equipment manufacturer in California recently offered another solution. Los Angeles-based Torus Hydro introduced an auto pH balancer device that claims to be effective in automatically regulating pH without the use of chemicals or the risk of pH swing when left unattended.

By definition, pH measures the hydrogen concentration in a water-based solution. While pH up/pH down dosing uses acidic/alkaline chemicals to correct hydrogen imbalances, Torus Hydro’s products use ionic technology directly attract and capture hydrogen ions as needed to balance this concentration.

According to Torus Hydro, balancing pH in this manner leads to a variety of benefits, namely eliminating the risk of detrimental pH swings, and maintaining an ionically healthier reservoir environment allowing for less frequent reservoir changes, greater nutrient absorption efficiency & increased yields.

We wanted to put these claims to the test, so we enlisted Scott at OperationFullSpectrum, an ACMPR-licensed cultivator in Alberta, Canada specialized in growing medicinal cannabis for the treatment of epilepsy. Scott has 16 years of experience in the field and is a regular expo panelist and speaker at events like the Canadian Cannabis Summit.

Torus Hydro offers two versions of their pH balancer device: a capsule filter that sits in the reservoir, designed for high-flow recirculating systems, and an inline filter that connects directly to a pump for use with low-flow recirculating systems as well as Drain-to-Waste set-ups.

Both versions are available in various standard sizes, suitable to treat setups ranging from 35 to 250 gallons. Torus Hydro also claims that multiple units can be used together in larger reservoirs.

For the test, Scott used the 70gal capsule model in a custom RDWC system with clay pebbles and used the 35gal Inline Edition in a Drip-to-Waste system by The Bucket Company with a coco / Supersoil mix.

THE GOAL

The test aimed to complete a harvest with each system, without using any pH up or down from beginning to end of the run, while maintaining pH between 5.8-6.2 without any significant pH swings outside of this range. The preference was that the pH would vary slightly within this range between each reservoir top-up, to allow various nutrients to be best absorbed over time as the plants would feed.

DRIP SYSTEM - SPECS & RESULTS

SYSTEM TYPE: Hydroponic Drip-To-Waste

SYSTEM: 18 x 3gal Planter by The Bucket Company + 50gal reservoir

MEDIA: Coco & Supersoil Mix

NUTRIENTS: Holland Secret by Future Harvest

STRAIN: Remo Chemo (Indica)

TOTAL PLANTS: 18

For the test with the 35gal Inline Edition, an 18-site drip-to-waste system by The Bucket Company was used, utilizing 18 x 3gal planters and a 50gal capacity reservoir. Remo Chemo, an indica known for its health benefits, was grown in a Coco/Supersoil mix, using the Holland Secret nutrient lineup by Future Harvest. The drippers ran for 1 minute twice a day, and the reservoir temperature was kept between 62-68 F.

Scott had used this setup before with the same variables, aside from using Torus Hydro’s device, growing a different strain (Sunset Sherbet, though he states the strain typically yields rather similarly to the Remo Chemo used on this run).

The 35gal Inline Edition was connected to a pump circulating the water/ nutrient mixture inside the 50gal reservoir. Tap water with a pH of approximately 7.5 was mixed with the Holland Secret nutrients, landing the pH at 6.1 when the nutrients and water were mixed. The reservoir had a large enough capacity for approximately 10 days of use before requiring a top-up.

THE RESULTS

Across the course of the harvest, the pH maintained stable and never exceeded 6.2 or fell below 5.8. The pH in the tank stayed steady, generally around 5.9-6.0, and the pH coming out of the drippers stayed within this same range. The pH of the runoff came out around 6.2-6.4, as was preferred, indicating that waste and salts were being removed from the system.

Typically, OperationFullSpectrum would utilize phosphoric acid throughout the harvest to moderate the pH, as it would occasionally rise out of range and need to be lowered. In the test, this was not required and the pH was maintained without any chemical additions.

In this system, OperationFullSpectrum would typically do a full reservoir change every 10-14 days during the vegetative stage, or every 7 days during flower, to remove salt buildup that would inhibit nutrient absorption. Scott observed that the PPM increase indicating the need for this reservoir change, as well as visual salt buildup in the reservoir, took longer to accumulate when using the device. This allowed reservoir changes to instead be performed every 21 days during veg and every 14 days during flower, helping to conserve usage of water and nutrients. Water/nutrients would instead just be topped up as needed during this time.

The total yield of the harvest, across both the drip-to-waste system and the RDWC system, totaled approximately 7.44 pounds, with 60% of this attributed to the drip-to-waste system. At about 4.46 lbs across 18 plants, this equated to approximately 3.96 ounces yielded per plant. Compared to his previous harvest with this system, growing Sunset Sherbet, Scott notes that he observed an approximate 20% increase in yield using Torus Hydro’s device with this system.

RDWC - SPECS & RESULTS

SYSTEM TYPE: RDWC System

SYSTEM: 12 x 5gal Bucket - Custom RDWC System

MEDIA: Clay Pebbles

NUTRIENTS: Holland Secret by Future Harvest

STRAIN: Purple Punch (Indica)

TOTAL PLANTS: 12

For the test with the 70gal Capsule, a 12-site custom RDWC system was used, utilizing 12 x 5gal buckets. Purple Punch, an indica cross of Grand Daddy Purple and Larry OG, was grown in a clay pebbles, also using the Holland Secret nutrient lineup by Future Harvest. The pump in the system ran 24/7, and the water temperature was kept between 62-68 F. Scott had also used this setup before with the same variables, aside from Torus Hydro’s device, growing a different strain with similar typical yield (Sunset Sherbet).

The 70gal Capsule was placed directly in the reservoir. Tap water with a pH of approximately 7.5 was mixed with the Holland Secret nutrients, landing the pH at 6.1 when the nutrients and water were mixed. The reservoir had a large enough capacity for approximately 10 days of use before requiring a top-up.

THE RESULTS

Across the course of the harvest, the pH stayed stable and never exceeded 6.2 or fell below 5.8. For this set up as well, OperationFullSpectrum would typically use phosphoric acid throughout the harvest to moderate the pH, as it would occasionally rise out of range and need to be lowered. In the test, this was not required and the pH was maintained without any chemical additions.

In this system, OperationFullSpectrum would typically do a full reservoir change every 14 days during the vegetative stage, or every 7 days during flower, to remove salt buildup that would inhibit nutrient absorption. Scott observed that the PPM increase indicating the need for this reservoir change, as well as visual salt buildup in the reservoir, took longer to accumulate when using the device. This again allowed reservoir changes to instead be performed every 21 days during veg and every 14 days flower, helping to conserve usage of water and nutrients. Water/nutrients would instead just be topped up as needed during this time.

The total yield of the harvest, across both the drip-to-waste system and the RDWC system, totaled approximately 7.44 pounds, with 40% of this attributed to the RDWC system. At about 2.97 lbs across 12 plants, this equated to approximately 3.96 ounces yielded per plant. Compared to his previous harvest with this system, growing Sunset Sherbet, Scott notes that he observed an approximate 15% increase in yield using the device with this system.

THE COST

Though pricier than pH up/down (the base 35gal capsule model starts at $115 in the United States), Torus Hydro says the device is reusable for repeated harvests. They sell a cleaning agent they call ‘Recharge Solution’, to recharge the unit by soaking the capsule model directly or filling the inline filter with the fluid and letting it sit for a couple of hours. They recommend recharging the unit every 2-4 months, but note that if using a larger unit in a smaller reservoir the unit can work effectively being recharged less often.

At $59 for a 500mL bottle of Recharge Solution (containing 4 recharges for the 35gal capsule) and $89 for a 1L bottle (containing 8 recharges for the 35gal capsule), maintenance cost for a 35-gallon system comes out to about $3 to $8 per month. They say this means the unit can pay for itself in time compared to pH up/down cost.

OperationFullSpectrum says they saved approximately $400 across this harvest, by not utilizing pH up/down and seeing less waste of water and nutrients, in addition to the increase in yields observed.

SUMMARY

In OperationFullSpectrum’s test, Torus Hydro’s device lived up to its claims and seems to be a viable alternative to chemical pH maintenance for hydroponic cultivators looking to reduce labor and cut costs. The downside of the device is that it is currently only compatible with mineral nutrients, and Torus Hydro claims compatibility with organic nutrients is still unconfirmed and in research & development.

Hydrogen peroxide also isn’t recommended with the device, so growers using it need to be aware of keeping water temperature in check instead to avoid root rot. If using silica, they recommend only to use a pre-stabilized brand, such as OSA 28. The entry price for the equipment is also a bit high, but the low maintenance cost does help offset this, and the possible cost savings in operational expenses and potential for yield increase can help to recoup the expense.

For more information check out Torushydro.com.