Najas Info
  Inside scoop from Aqualand on Najas guadalupensis (probably)


 Najas (also called guppy grass) Factoids


Other Names Southern naiad, southern water nymph, common water nymph
Naiad Greek for water nymph


Room temp fine
Lighting Medium to high
Best Use Makes a great cover plant for small fry = guppy grass

Biggest Threats

Cichlids, plecos, apple snails, medications, and koi


Grows and grows


Fish wastes seem to work.  CO2 not needed.


Nearly immaterial
In the Wild Likes shallow water, wetlands, marshes
Invasive Pest* Hinders swimming, fishing, boating in southern states
*Which means it should grow in your tank.

Pieces of Najas guadalupensis
appeared floating in many tanks (probably brought in by a customer)

Where Does Najas Come from?  Well, it just magically appeared one day in a few of our aquariums.  I couldn't remember its name because I haven't seen it in ages.  It used to be fairly common back in the olde days.  In fact, I'd seen it wrapped around my fishing line when I was drowning worms at our local reservoir (Maffett Reservoir).  I hadn't seen it for so long, I had to look it up (not on the internet) but in an actual book named Oriental Aquarium printed in Singapore.  I've decided it's the guadalupensis species.  It's not available commercially.  It tends to break apart when gathered into retail bundles.

Very rudimentary root system -- or none.

Roots not Really Needed?  Najas guadalupensis roots remind me of cabomba roots.  Najas roots grow higglety pigglety whichever direction they please.  Many floating Najas plants don't seem to grow roots at all.  Or, perhaps they just broke off?  Lots of water plants get along without roots.  They absorb the nutrition they need thru their leaves.

Small fish and other critters can hide in the Najas guadalupensis forest.

Great Cover Plant.  Young livebearers instinctively head for the "bush" so their parents and their in-laws will not invite them for lunch.  Little fry and other small critters can also sort thru the Najas forest in search of what the Germans call "aufwuchs" -- what we call tiny animalcules (single-cell and up) that cover most surfaces in an established aquarium.

Chlorophyll at work.

Good Oxygenator.  Growing Najas plants in a well-lit tank take in CO2 and give off O2.  They pretty much do the opposite at night, but any water circulation serves to level out both processes.  Today's filters and aerators obviate the need for oxygenating plants.

Your fish will fertilize your Najas guadalupensis.

No Fertilizer Needed.  Your community fish kick out sufficient urine and CO2 to keep your Najas growing.  These foods also fuel algae and diatom growth.   Najas can usually out compete algae in the absence of excessive (too much wattage or too much time) light.  The Najas leaves also shade the potential algae just waiting to gain a foothold.  Because unrooted Najas usually floats at the surface, it absorbs more light than bottom plants.  If algae already has a grip, Najas will not get rid of it.  Use nerite snails, i.e, Tiger Nerite or Olive Nerite for algae removal.


Last Words.  Water changes definitely perk up most water plants.  Our local water contains lots of carbonates (magnesium and calcium) that fish and plants (Najas guadalupensis) seem to like.  You'll not likely find it for sale in your LFS because it breaks apart so easily.  LA

About a month later.


2012  LA Productions


3600 Sixth Avenue

Corner of Sixth & Euclid Avenues

Des Moines, IA 50313

515 283-0300



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