250W MH/HPS Cannabis Grow Setup & Tutorial

Updated Jan 24, 2021

by Nebula Haze

250W HPS grow lights

See More Growing Setups


250W HPS Grow Setup (For Hobbyist Growers)



About This Setup

The 250W HPS is one of the best (if not most popular) setups a grower can use for small-scale indoor growing. It delivers impressive yields, high potency, lower starting cost, and it’s easy to use since the light can get so close to plants. The 250W also escapes much of the heat issues that larger models of HPS have, though they still have that tell-tale color that can alert people to your grow if it escapes the tent.

Pros: Cheap, easy to use, great yields, awesome potency

Cons: Harder to find, old-fashioned, harsh yellow light is easily distinguishable as a grow light

My last harvest with a 250W HPS grow light (dry yield was 8.97 oz) – View a video of the plants just before harvest

250W HPS grow tent before harvest


Cost Estimates

  • Total Setup Cost: $775.00
  • Estimated Electricity Cost: $21-43/month (based on $0.12/kWH to $0.25/kWh – see breakdown)
  • Total Cost for Entire First 4-Month Grow (Setup + Electricity): $947 ($105-236/ounce)
  • Total Cost for Second Grow (Nutrients + Electricity): $225 ($25-57/ounce)

Note: Because the 250W light runs significantly cooler and tends to grow smaller plants compared to the bigger HPS grow lights, the 250W setup uses a cheaper exhaust fan and carbon scrubber compared to the other HPS setups, which brings down the overall cost a bit.



Complete Grow Supply List

This cannabis grow room setup list includes all the supplies you need to grow from seed to harvest.

250W MH/HPS Grow Light (ballast, bulbs, and reflector sold separately)

  • BallastYescom 250W MH/HPS Digital Ballast
  • Bulbs250W MH bulb250W Super HPS bulb. This “Super HPS” bulb puts out significantly more light than the generic HPS bulbs so don’t skimp. If you must choose just one bulb, get just the HPS. An MH bulb helps plants stay shorter and get bushier if used in the vegetative stage, but an HPS bulb can be used from seed to harvest in a pinch.
  • ReflectoriPower Gull Wing Reflector. I’ve tried several different reflectors with this setup and I’ve found the wing reflector (despite being the cheapest option) actually gets more light to more parts of the tent with a 250W HPS than the more expensive air-cooled hood reflecter or cool-tube reflector. Just be aware that a wing reflector is flimsy and bendable. If that would bother you, go with the sturdy air-cooled hood reflector.

Cost: ~$190

A 250W HPS is a great grow light for beginners. Plants grow quickly and produce excellent bud quality, density, and yields.

Example of a "bat wing" reflector for growing cannabis with an HPS grow light

* Alternative all-in-one 150W HPS – This light is significantly smaller (it uses 100W less), but if you want a cheap “all-in-one” grow light kit with the ballast and reflector built together…

Grow Tent (recommended sizes)

Cost: ~$100

Learn more about grow tents

6″ Exhaust Fan 

An exhaust fan vents hot air and can be combined with a carbon filter to stop all smells from leaving the grow space. The 6″ size is plenty for a 250W.

  • Example 1: Cheap but loud VIVOSUN 6 Inch 390 CFM exhaust fan. If you plan to use a carbon filter to stop smells, it’s typically cheaper to get a kit that contains both the fan and filter than to buy them separately. Avoid “booster” fans that cost under $35. Although they seem like a good deal, they’re not powerful enough to properly vent heat or use a carbon scrubber. I’ve tried.
  • Example 2: Quiet but expensive AC Infinity CLOUDLINE S6 or CLOUDLINE T6 (T6 version is the same fan but has a digital interface)
  • Learn more about setting up an exhaust fan

Cost: ~$110 ($65-140)


Carbon Filter / Scrubber (optional)

Used with an exhaust fan to remove weed smell from the air. When set up properly, a carbon filter removes 100% of odors.

Cost: ~$80


Plant Pots

I prefer fabric pots or air pots because cannabis plants grow faster. However, standard hard-sided plant pots also work well and can be watered less often.

Cost: Less than $30

Plants grow faster in fabric pots compared to hard-sided pots


Grow Medium (Soil, Coco, Hydro)

Examples include coco coir or soil (hydroponics for more advanced growers)

Cost: ~$40


Many nutrient systems have a nutrient schedule so you give your plants the right ratios for each stage of life. Basically you use a “vegetative” or all-purpose plant nutrient for the first part of your plant’s life and a “bloom” or low-nitrogen nutrients when buds are forming.

Tip: Always start at half strength with a new base nutrient system since the recommended amount can be too high for cannabis plants.

Cost: $50-85

See examples of other great cannabis nutrients.

General Hydroponics Flora trio - includes all your base nutrients! General Hydroponics CaliMagic Cal-Mag supplement
General Hydroponics Flora Trio and CaliMagic


See a list of recommended seed sources here.

Example of feminized cannabis seeds - every one grew into a female plant!

Other Nice-to-Have Stuff

Learn about other cool growing tools

Estimated Cost: $775 plus the cost of seeds

See Additional Grow Setups

2 days after auto-flowering cannabis seedlings sprouted under 250w HPS

Auto-flowering cannabis plants at week 6 - cozy in their tent!

From left going clockwise: Dinafem Critical Jack, Dinafem Sour Diesel, Dutch Passion Blue AutoMazar

Got a 6+ oz Harvest! Read the tutorial on how to grow exactly like this! (in this setup)

Example of a possible harvest with a 250W HPS

A hydroponic plant grown in this setup (6+ oz harvest!) – Read the grow journal!

Original Amnesia cannabis plant under a 250W light

These plants were grown under a 250W HPS. Here’s the grow journal (the 250W HPS beat LEDs in a side-by-side experiment, check it out!)

Example of 8 different autoflowering cannabis strains grown in a grow tent

More plants I grew under a 250W HPS in this setup

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