House & Garden Algen Extract, 20 L

A Cold-Pressed Sea Kelp Supplement for an Existing Feeding Program, 20 L

Heat-processed kelp extracts lose some of the natural compounds that make seaweed a useful supplement in the first place, since heat and high-pressure extraction can break down the plant hormones and trace elements kelp is valued for. House & Garden Algen Extract is made from Norwegian sea kelp using a cold-press process instead, intended to keep more of the raw material's natural compounds intact than a heat-extracted alternative.

This 20 L bottle is sized for a larger indoor grow room or commercial operation supplementing many plants at once. Algen Extract is a supplement layered onto an existing base nutrient program rather than used as a standalone feed.

Key Features & Benefits

• Norwegian sea kelp source — sourced from cold-water kelp rather than a generic seaweed blend
• Cold-pressed extraction — intended to preserve more of the kelp's natural compounds than heat-based extraction methods
• Supplement, not a standalone feed — designed to be added alongside an existing base nutrient program
• Available in 20 L — sized to match the scale of the operation using it

Who Should Use Algen Extract

Growers already running a base nutrient program who want to layer in a cold-pressed sea kelp supplement will use Algen Extract as an addition, not a replacement, for their existing feeding schedule.

About House & Garden

House & Garden is a nutrient and additive brand established in 1990 by William Van De Zwaan, whose family had a background in Dutch horticultural glasshouse production; the company formulates its base nutrients and additives in small batches, filtering its process water through multi-stage ceramic filtration. Hydrofarm acquired House & Garden in 2021, and the brand's manufacturing and research operations are based in Humboldt County, California, building a product line of base nutrient systems and root, flowering, and growth additives sold to growers in dozens of countries.

Frequently Asked Questions

What is Algen Extract made from?

It's made from Norwegian sea kelp using a cold-press extraction process. Cold pressing is intended to preserve more of the kelp's natural compounds than heat-based extraction methods.

Do I still need my regular base nutrients?

Yes. Algen Extract is a supplement designed to be layered onto an existing base nutrient program, not used as a standalone or complete feed on its own.

How is cold-pressed extraction different from other kelp products?

Heat and high-pressure extraction methods can break down some of the natural compounds in raw kelp, including plant hormones and trace elements. Cold pressing avoids that heat exposure, which is intended to keep more of those compounds intact in the finished product.

When during the growth cycle should I use Algen Extract?

Algen Extract is formulated as a general supplement rather than a stage-specific additive, so it can be layered onto a base feeding program throughout vegetative growth and flowering. Follow label directions for dosing at your reservoir size.

How do I add Algen Extract to my reservoir?

Mix it into your reservoir water alongside your base nutrients, following the label's dosing directions for your reservoir size. Measure with an EC/PPM meter as you would with any other additive in your feeding program.