Specializing in indoor gardening and hydroponics growing!

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Growco Indoor Garden Supply has been supplying growers with the best quality organic fertilizers, hydroponics systems, and indoor gardening supplies since we opened our first retail store in 1999! Large Orders

We now have two incredible retail stores in West Michigan, and a dedicated full-time warehouse for our internet customers. We stock all of the items that you'll find on this website at the lowest possible price, and we always ship orders out on same day we receive them or on the next business day! We specialize in complete growroom packages, and we will gladly take the time to help you build the growroom of your dreams! Large orders, pallets of soil- whatever you need for your indoor garden- you've come to the right place, we're here to help!

Emerald Harvest

Mills Nutrients

Featured Products

Unique double ended constructions allows doe maximum optical efficiency and uniformity.
Ozone is great at removing smoke, or strong pet smells. It kills mold and mildew in basements, and can eliminate powdery mildew on plants.
Heavy duty 5 gallon measuring bucket that is perfect for a variety of garden-related tasks.
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The Nextlight Mini LED Growlight is a small bulb that runs on just 150w, the Mini is a powerful LED Growlight that sports the full, highly-acclaimed NextLight full spectrum.

Newest Additions

Introducing the brand new 1000 Watt Double Ended HPS grow lamp from Hortilux: a top-of the line product featuring the exclusive Eye Hortilux spectrum.
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The MEGA LED Growlight from NextLight is a high intensity, full spectrum light guaranteed to replace any DE 1000w HPS on the market with a better energy efficiency rating and a larger footprint.
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The NextLight VEG8 Growlight is an energy efficient replacement light that performs just as good if not better than your existing fluoresent 8 tube T5.
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The Nextlight Mini LED Growlight is a small bulb that runs on just 150w, the Mini is a powerful LED Growlight that sports the full, highly-acclaimed NextLight full spectrum.
To harvest your biggest yield yet, you're going to need plant stalks that can handle your heavy blooms and fruits. While your base nutrient series provides basic supplements necessary for strong stalk growth, Sturdy Stalk, a potassium silicate supplement from Emerald Harvest, gives your plants the extra boost they need to grow strong enough to withstand stressors from the environment and elsewhere.
$14.25 - $43.95
Introducing Emerald Harvest's Cal-Mag, a top of the line calcium and magnesium supplement perfect for perking your plants back up to a lush green state.
$29.95 - $109.95
Emerald Harvest's King Kola is a revolutionary bloom boosting supplement that leads the hydroponic industry by adding hemp seed flower for additional nutrients essential to your plants' bloom.
For plants with fragrant, sticky buds and all kinds of trichomes, look no further than Emerald Harvest's Honey Chome. A top-of-the-line aroma and resin enricher, Honey Chome combines the best natural ingredients to ensure your plants smell and taste great.
For a hydroponic garden full of high-yield plants, you'll need an effective and comprehensive nutrient supplement. Emerald Harvest's Emerald Goddess does just that.
Unleash the genetic potential of your next harvest with Cali Pro Bloom A and B by cultivating a robust, fragrant garden full of the largest flowers.
If you're looking for stronger stalks and stems that can support the robust harvest you're looking for, then Emerald Harvest's Cali Pro Grow A and B is what you're looking for.
$12.75 - $29.95
Emerald Harvest Micro makes sure your plants get all the right micronutrients, in addition to a balanced diet of Nitrogen, Phosphorous, and Potassium.
$10.95 - $24.95
If you're looking for bigger, better flowers that increase your overall yield this season, then make sure to add Emerald Harvest Bloom to your base nutrient system.
$10.25 - $24.95
Emerald Harvest Grow is the first in this three step nutrient system specially created to help accelerate your plants growth.
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Organic Bountea Humisoil is the perfect super soil blend for indoor or outdoor applications. It's organic certification makes it gentle on all plants!

We always ship in heavy-duty plain brown boxes, and our 15 years of shipping experience help to insure that you will receive your order intact and undamaged every time! We warehouse all of our products, and pride ourselves in getting your order to you fast!

Our staff has many years of hands-on experience
helping customers build grow rooms, dial in nutrient programs, and make seriously productive gardens. Huge selection, low prices, and fast shipping- Growco wants to be your favorite grow shop! Let us help you learn to grow like a pro!

Private, secure online ordering. No registration needed to order. We strive for your complete satisfaction - we want to be your "go-to" source for performance gardening supplies!

Why shop at 4hydroponics.com?

  • FREE shipping on most orders $250 or more when delivered in lower Continental USA.
    (Sorry, Alaska and Hawaii not included.) Oversized or heavyweight items not included.
  • NO sales tax when delivery is outside of Michigan. In some states that's a 10% savings!
  • VERY competitive pricing.
  • No registration needed to place an order.
  • When we ship your order, magazines or catalogs are liberally included. (More info)
  • Read customer feedback here.

Shipping to Michigan? Expect delivery within 2 business days!

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Garden Watchdog Top 5 Organic Seeds in stock Hydro for Hunger participant OMRI Listed
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