Aquaponics Application

South Mountain MicroFARM

Owner: Levi Sellers

6138 Clevelandtown Rd
Boonsboro, MD 21713
Washington County

daytime phone: (240) 675-2542
Web site:

Application Date: 2017-04-03

Applicant Details

Please briefly tell us why you are applying to be part of the Certified Naturally Grown program: *
We grow naturally using a Nelson and Pade Clear Flow Aquaponics System and we look forward to being Certified Naturally Grown because there is great value in the certification where it creates awareness and confidence in the products we grow.
Are you currently third party Certified for your produce operation by any other organization (Organic, Biodynamic, etc)? *
Have you ever been certified in the past? *
Have you ever been denied certification? *
How did you hear about Certified Naturally Grown? *
We first learned about Certified Naturally Grown through Nelson and Pade training seminars that we attended.

General Information

Please check all crops you grow in your aquaponic system. *

Please specify what other crops (if any).
Please check all markets you grow for (this will be displayed on your farm profile to help potential buyers find you). *

Please specify what other markets (if any).
Public school system & on our farm

System Design and Management

Please indicate what type of system you use (for hybrid systems, check all that apply): *

If you indicated you use an "other" system type, please specify what other type of system you use here.
We use Nelson and Pade's Clear Flow Aquaponics System with ZDEP (zero waste/extra production)
If you use wicking beds, describe how the water his handled after it is used in the wicking beds. Does this water recirculate? If not, how is it disposed of?
What materials are used for root support, growing media, tubing and pipes, tanks, troughs, and other materials that come into direct contact with system water? (check all that apply) *

Are there any other materials you use in your system that are not listed above? If so, please indicate them here.
potable water grade liner NSF certified PVC pipe
If you use soil or compost in your system, where is it used? Is it used only in the dead-end portion, or also in in the recirculating sections of the system?
No soil or compost
If you use compressed grow plugs, what is (are) the product/s name/s? Have you been able to confirm with the supplier that it/they do not contain synthetic nutrients?
No compressed grow plugs. We use rockwool.
If your system contains cement, does it come into direct contact with the water? Please describe how cement is a part of your system.
No cement
If you use wood in your system, is it treated wood? Does it come into direct contact with the water? Please describe how wood is a part of your system.
We use cedar wood stands for our tanks and there is no contact with the system water.
If your system includes IBC totes purchased used, have you been able to confirm with your supplier that they were used only for food grade uses? If so, how have you confirmed this? If not, how do you intend to confirm this?
No IBC totes.
Please note that while IBC totes can be grandfathered in when they're in already in use at the time CNG certification is sought, CNG standards prohibit the introduction of IBC totes once CNG status is obtained. Please indicate that you understand this restriction on IBC totes by checking the box here. *
Does water circulate at a rate sufficient so that the water volume of the fish tanks(s) recirculates each hour? If it recirculates at a lower rate, please explain. *
Briefly describe how your system achieves appropriate aeration. *
We aerate 24/7 with blowers and air diffusers in the fish tanks, degassing tanks and raft tanks.
Briefly describe how your system achieves appropriate degassing. *
We have a separate vessel for degassing. It is aerated 24/7.
Does your system include any of the following: roofing materials, recycled plastics, or plastics that contain BPA? *

Water Sources

CNG standards vary according to water source. Please indicate below ALL water sources you use for your aquaponic system, and answer the corresponding questions.
Do you use Municipal water? *
Do you use well water? *
What are the ground water contaminants of concern in your region? *
None known
What experts did you consult to determine contaminants of concern? *
Well drillers and county data
Have you tested your well within the past year, and if so, what were the results? *
We regularly send system water samples for analysis to Micro Macro International in Athens, GA, an agricultural lab. The most recent was 12/19/2016. The test included: Nitrate-Nitrogen, Ammonium-Nitrogen, Phosphate, Potassium, Calcium, Magnesium, Iron, Manganese, Boron, Copper, Zinc, Molybdenum, Sodium, Nickel, Aluminum, Silicon, pH, EC, Chloride, Fluoride, Sulfate, Carbonates, Bicarbonates, Alkalinity(mgCaCO3/liter). We don't have other known "contaminants". We also had our county health department water test done for the well in 2015 with no issues or contaminants. We plan to continue testing the well at least once annually.
Are you willing to start testing annually? *
Do you treat or filter the water before adding it to the system? If so, what methods are used? *
Yes, we have a UV system.
Do you use rainwater? *
Do you use surface water? *
If you use a water source that is not named here, please elaborate.
We do not use any other water source.

Water Quality: Nutrients, pH, solids

How do you ensure a good match between stocking density and crop production? *
We operate a Nelson and Pade Clear Flow Aquaponic System and follow their proven science-based formulas that they developed over the past 20 years. Our fish stocking is designed to support a specific vegetable crop load.
Please describe how you design and operate your system to provide biofiltration that corresponds to production of fish waste and crops. *
We have nitrification tanks and mineralization tanks sized for our system and we allow nitrification to happen throughout the system. We monitor ammonia and nitrite to make sure the levels are safe and we consistently have safe levels.
Do you ever add supplemental nutrients? If so, what materials or products have you used? List ingredients and product names. How much of these do you use? How frequently? *
Chelated iron, as needed.
Do you use worms in your system? *
What materials do you use to buffer pH? *
Occasionally we raise pH with potassium hydroxide and calcium hydroxide.
What methods do you use to prevent the build up of waste solids in your system? *
We remove solids via clarifiers and Nelson and Pade's ZDEP system where the waste is collected from the clarifiers, processed and the fresh nutrient-rich water is returned to the system.
Please indicate how often you monitor each of the following:
pH? *
Temperature? *
Dissolved oxygen? *
Ammonia? *
Nitrites? *
Nitrates? *
Use this space if you'd like to share additional information about your water quality and monitoring practices.
We follow Nelson and Pade's standard protocol but based on observation if we see the need we will test more frequently.

Seeds, Transplants, and Crop Health

Do you grow some or all of your own transplants? *
What growing media do you use? Please list the ingredients. *
1" and 1.5" rockwool cubes
Do you use any chemically-treated or genetically modified seeds? *
Do you purchase some or all of your transplants? *
Describe your primary insect pest challenges AND methods of prevention and control. (Do not answer "none". You MUST indicate actual pest challenges or LIKELY challenges, and you must ALSO indicate how you manage or how you would manage them. If you indicate a product, also specify how often it's used.) *
Thrips, Aphids, and whitefly. We have strict bio-security protocol and insect screening for prevention. We monitor and scout daily to look for pest problems. We use biological control for pest insects.
Describe your primary plant disease challenges AND methods of prevention and control. (Do not answer "none". You MUST indicate actual disease challenges or LIKELY challenges, and you must ALSO indicate how you manage or how you would manage them. If you indicate a product, also specify how often it's used.) *
All our crops start from seed to prevent transmission of diseases from other facilities. We don't have other plant disease issues in our controlled environment greenhouse.
CNG certification requires the use of certified organic or Certified Naturally Grown seeds whenever available. Please indicate the suppliers from which you source - or will source - your seeds if your application is accepted and you continue the certification process. *
Johnny's Seeds (MOFGA Certified Organic)
Please indicate, by entering your initials, that you understand that CNG strictly prohibits the use of chemically treated or GMO seeds. *
Please indicate, by entering your initials, that you will as a general rule purchase organically grown seeds, AND that you will only purchase conventional seed when the variety you wish to grow is not available in certified organic or CNG form. For each variety purchased in conventional form, you will identify (and keep records of) at least three commercial organic seed suppliers who do not carry that variety. *

Fish Management

We do not offer certification for fish, but do set some limited standards for fish management where they might affect the produce and or quality of life for the fish.
Does hormonal sex reversal treatment ever occur on-line / within the recirculating system? *
Please describe the practices you use to prevent and treat fish disease.
We have strict bio-security as a preventative measure. If we have to treat a fish, we move it to a separate hospital system. To date we have never treated with anything other than salt and temperature manipulation.
Have you ever found it necessary to use antibiotics? *
Please describe what kind of fish feed you use. Is it organically grown? (For aquaponic produce certification CNG standards do not require that the feed be organically grown, but we are interested to know what producers are using and to give credit to any producers who may be using organic feed) *
We feed Zeigler FinFish and Silver fish feed which is sustainably sourced.
Do you use black soldier fly larvae or duckweed as supplemental feed? *
Do you use any supplemental feed besides BSF larvae or duckweed? If so, describe it here, and indicate how you protect against contamination of your system. *

Protecting Against Contamination

Is your operation partially or entirely INdoors? *
What are the nearby land uses? Are there any that might pose risks of contamination? *
Our Aquaponics greenhouse is on our 22 acre all natural Christmas tree farm with small farmettes nearby with a few cattle and horses to our west and north and woodlands to our north and south. There are also a few homes near by. We do not use any herbicides or pesticides on our Christmas trees or the farm. We are not near any manufacturing or industrial pollutants.
How does your ventilation and air filtration system prevent possible contamination? *
We are in a controlled environment greenhouse and we bring in fresh air for ventilation.
Do you share space (including fish tank, seedling starting, or plant production space) with other producers? *
Is your operation partially or entirely OUTdoors? *

Waste & Energy

These questions will not determine certification status, but are intended to encourage producers to review our recommendations in these areas and to give credit to producers who have made investments in the sustainability of their operation.
How do you dispose of fish solid wastes? *
We have zero waste in our system. All fish waste is 100% utilized for plant growth.
When necessary during system change over, how do you dispose of nutrient-rich water? *
We use a Nelson and Pade Clear Flow Aquaponic System with ZDEP which captures and processes system wastewater, bringing fresh nutrient water back into the main system and utilizing the remaining water and solid waste to grow additional crops in our Nelson and Pade Living Media beds. This eliminates the need to discharge water from our aquaponic system. Drain water from sinks and washing in the greenhouse goes into our septic tank on the property.
What measures have you taken to conserve energy, improve energy efficiency, and/or use energy from renewable sources? (This could include system design, siting, insulation, crop and fish species selection, and more.)
The location of the greenhouse on our property is on the side of a hill which allows fresh air flow from the west almost all the time. Our entire West wall opens and our roof vents open to the east to allow passive ventilation for the greenhouse for cooling and also to help control humidity. All of our lighting is LED including the grow lights which are 325 watts vs. 1000 watt HID lights. We had a Wadsworth EnviroStep controller to efficiently control temperature, humidity, lighting, and snow melt from the roof. About 1/3 of our greenhouse, the north end, is insulated and covered with insulated metal roofing. The remaining area uses dual layer polycarbonate which is energy efficient. We use a propane on-demand water heater vs. electric, to heat the system water which is very energy efficient. We use 3 vertical air flow fans vs. 8 horizontal fans for cooling and the vertical air flow fans also control our humidity vs. a mechanical dehumidifier. The Wadsworth controller operate the grow lights only turning them on as needed based on natural light conditions. We have insulated vertically around the outside perimeter of the greenhouse. We use a shade cloth that runs the entire length of the greenhouse to control overheating in the summer and in the winter it is closed to maintain the heat and allows us to heat a smaller area.

Inspections & Networks

A core requirement of CNG certification is the on-site peer-review. Getting this completed is facilitated if you're a part of a network of aquaponics producers who might serve as your inspector. Are you a part of a network (informal or formal) of aquaponic producers in your geographic area? *


I understand that only the produce, NOT the fish, can be labeled and sold as Certified Naturally Grown. *
I will not label, or in any way lead consumers to believe that produce not raised in accord with CNG standards is Certified Naturally Grown. *
I understand that I have to complete at least one Inspection(s) of another CNG aquaponic producer in my area each year, if there is one within a one hour drive. *
I understand that the inspection I conduct will NOT be of the same producer that inspected me. *
I have reviewed the Certified Naturally Grown aquaponic certification standards, I understand them, and I will abide by them. I understand that if I have any questions I may contact CNG for clarification. *
You may use this space to tell us anything else you think we should know about your operation.