Once hydroponic growrooms are up-and-running, these operations still require money to function. For the indoor gardener, the constant use of high-powered lighting, fans, air conditioners, and pumps directly converts into bigger electric bills.

Furthermore, there are several hidden expenses within the everyday operation of a hydroponics garden: rent, water, materials, and nutrients. For the prudent cultivator, it is possible to break down these costs into quantifiable expense categories—giving them insights into their operational overhead.

In the ideal situation, practical hydroponic gardeners can highlight unnecessary spending through this analysis and adjust their operations accordingly.

In order to calculate the operational expenditures of growing an indoor hydroponic crop from seed to harvest, a hypothetical cultivation scenario is required to provide a structural example.

Therefore, this analysis will be based on an active ebb and flow hydroponic flood table system that constantly recovers and recycles unused water and hydroponic nutrients.

The numbers involved in this cost analysis are taken from a theoretical 10,000W hydroponic flowering room with rent and utility expenses based on US averages.

With this notion in mind, here is a simple guide for breaking down costs on a nine-week flower cycle:

Rent and Mortgage

Rent and mortgage costs should be included in the pricing of an indoor cultivation operation because these gardens generally require a great deal of square footage. Indoor gardeners must rent or purchase homes with far more space than required for their normal living needs.

According to nationally accredited rental companies, the average price for a rental property in the US is $1,500 per month. For simplicity’s sake, one can assume that one-quarter of the home will be used for cultivation, resulting in $375 per month in rent expenses.

Total rent charges for a nine-week crop: $843.75 (based on US averages).

Electricity

Electricity rates fluctuate greatly throughout the country—with some power companies charging inflated tiered rates for high-power users such as indoor gardeners. Nonetheless, paying attention to the kilowatt hours used, as well as fluctuating rate systems for daylight hours and seasons, will give a solid foundation for analyzing one’s own costs.

According to a qualified source, $0.13 per kilowatt hour is the average cost of electricity in the US. To place this number in context, our hypothetical 10,000W grow room uses approximately 5,000 kilowatt hours a month, with a running cost of $650 per month.

Total electrical charges for a nine-week crop: $1,462.50 (based on US averages).

Water

The price of water per gallon can vary significantly, according to a number of factors bound to geography and environmental availability. However, following these mathematical examples provides a framework for computing water expenses on an individual basis.

According to a national database, the average water cost for a US citizen is $1.50 per 1,000 gallons. In our hypothetical 10,000W growroom scenario, a cultivator must keep a 100-gallon reservoir full at all times to keep the system functioning properly.

This is because, with a 25 per cent evaporation rate, one can count on losing 25 gallons a day, or 175 gallons a week, to evaporating water. Moreover, vigorously growing indoor plants in a 10,000W room can easily consume 40 gallons of water every other day, or 160 gallons in a week.

Finally, in an active hydroponics system it’s a good idea to clean one’s reservoirs once a week to ensure a consistent pH level—using another 100 gallons a week. As a result, the indoor hydroponic gardener can count on using 3,915 gallons of water in nine weeks for a 10,000W flower room.

Total water charges for a nine-week crop $5.87 (based on US averages).

Grow Mediums and Seeds

The most popular and affordable growing medium for an active hydroponic system is rock wool cubes. It should be noted that the choice of rock wool cubes is purely subjective, but the example provides a logical format for pricing techniques.

Following our hypothetical 10,000W growing set-up, let’s assume that each of the 10 1,000W lights will have nine plants. Six-inch rockwool cubes cost about $3.30 a piece, with a total cost per light of $29.70, or $297.00 for the whole grow room.

Total grow medium expenses for a nine-week crop: $297.00.

When it comes to choosing what sort of crops one wants to grow hydroponically, there are a plethora of options. In order to generate a concise number, let’s assume that our hypothetical operation is growing heirloom tomatoes.

Two grams of excellent heirloom seeds will cost around $18.00.

Nutrients and CO2

There is literally a surplus of options of excellent nutrient lines on the market today, and they will all probably will yield pretty good results. It should be noted that, in time, each indoor gardener develops their own nutrient recipe that works for their particular crop as well as infrastructure.

However, for the novice hydroponics enthusiast its best to follow the feeding charts provided by nutrient companies. After some market research, findings show one of the most affordable feeding schedules comes in at about $324.00.

As a result, a low-end nutrient cost for a nine-week ebb and flow hydroponics crop is $324.00.

The use of CO2 enrichment is not necessary for the beginner indoor gardener. Nonetheless, once one has their feeding schedule and climate perfected, the use of CO2 can greatly increase the size of a yield. A 20-pound CO2 tank costs $30.00 to fill and will last for about 3.5 days in a sealed room.

Therefore, the total CO2 expenses for a nine-week crop are $540.00.

Additional Materials

While every indoor cultivator has a different idea of what items are “essential” in growing a healthy crop, all growers use additional materials for plant support and pest control. A 10,000W room requires six 5x15-foot pieces of trellis netting for two layers of canopy support throughout the entire grow room.

The cost of this trellising is about $10.00 per unit, or $60.00 total. In addition, for pest control and mildew control neem oil is an effective and inexpensive spray that can be sprayed on plants throughout their life cycle. One pint of neem oil is approximately $15.00.

Total costs of additional materials for a nine-week crop are $75.00.

Conclusion

According to our figures, one can count on a nine-week, 10,000W, active/ebb-and-flow hydroponic crop costing a minimum of $3,556.12 to produce.

While different indoor gardeners have different theories on what counts as an expense (rent/mortgages expenses often being a source of contention) this analysis has provided a bare-bones guide for understanding why hydroponic gardening can be expensive.

Moreover, if the savvy horticulturalist gives critical attention to rent/mortgage expenses, kilowatt hour rates, water price per gallon, and nutrient feeding schedules, they can make some educated decisions concerning budgeting and expenses.