Back to Water Fern fish guides

Is Water Fern a Good Plant for Electric Blue Johannii?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Water Fern is not recommended for Electric Blue Johannii. The issue is practical, not cosmetic: electric Blue Johannii is likely to chew or tear this plant before it settles in.

Water Fern

Azolla filiculoides

View plant profile
PlacementFloating
LightModerate
DifficultyBeginner
Size1.5 × 2.5 cm

Electric Blue Johannii

Pseudotropheus johannii

View fish profile
TemperamentAggressive
FamilyCichlids - African
Temp24–28°C
Water TypeFreshwater Only

Quick Decision

A plant can be technically compatible with a fish and still fail in the actual tank if the fish digs, chews, needs denser cover, or uses a different part of the layout.

Overall fit

42/100

The fish is likely to outgrow, uproot, or out-pressure the plant.

Water match

Workable overlap

Shared range: 24-28°C, pH 7.8-8, 10-15 dGH.

Plant pressure

High

Electric Blue Johannii may chew, uproot, or stress this plant.

Layout value

High cover

Water Fern helps with provides surface cover, good refuge for fry, good refuge for shrimp, good grazing surface, and useful spawning site.

Plant and Fish Fit Notes

Use these signals to decide whether the plant is doing useful work for the fish, or whether it is only surviving beside it.

Temperature
Water Fern10-30°C
Electric Blue Johannii24-28°C

Overlap: 24-28°C.

pH
Water Fern5-8
Electric Blue Johannii7.8-8.6

Overlap: pH 7.8-8.

Hardness
Water Fern2-15 dGH
Electric Blue Johannii10-25 dGH

Overlap: 10-15 dGH.

Water and flow
Water FernFreshwater Only, Low (Still Water)
Electric Blue JohanniiFreshwater Only, Moderate (Standard)

Flow expectations are close enough for one layout.

Space used
Water FernFloating
Electric Blue JohanniiMiddle (Open Water) and Bottom (Substrate)
Pressure signals
Water FernLow uproot resistance, Delicate leaves
Electric Blue JohanniiAggressive, Generally Aggressive, Aggressive to same species/look-alikes, and Territorial (Defends specific area)

Plant pressure: High.

Planting value
Water FernProvides surface cover, Good refuge for fry, Good refuge for shrimp, Good grazing surface, and Useful spawning site, No substrate required
Electric Blue JohanniiSand (Sifters) and Established Algae (Otocinclus)

Shared Tank Conditions

Water Fern fits inside the water range normally used for Electric Blue Johannii. The shared window is about 24 to 28 °C, pH 7.8 to 8, and 10 to 15 dGH, which gives you enough room to aim for stable middle-ground conditions.

Their flow expectations are close enough to combine: Water Fern prefers gentle, low-flow water, while Electric Blue Johannii prefers moderate flow.

Both are suited to freshwater, so salinity does not add an extra planning problem.

Fish Pressure and Plant Resilience

Electric Blue Johannii puts heavy pressure on plants, so this species is likely to be chewed, uprooted, or stressed in day-to-day use.

Water Fern has high cover density, low uproot resistance, and delicate leaves. It can also help with surface cover, fry refuge, shrimp refuge, grazing surfaces, and spawning sites.

Its structure adds useful refuge value beyond the normal visual role of the plant.

The limiting issue is electric Blue Johannii is likely to chew or tear this plant before it settles in.

Layout Fit

Water Fern is a floating plant usually used floating.

Electric Blue Johannii is an African cichlid, so the pairing works best when the planting style supports how that fish uses space and cover.

Water Fern reaches about 1.5 cm tall by 2.5 cm wide and is usually free-floating with no substrate required. That makes placement and anchoring more important than simply adding a larger bunch of stems or leaves.

In this pairing, the useful plant values are surface cover, fry refuge, shrimp refuge, grazing surfaces, and spawning sites. Place it where Electric Blue Johannii can actually use that structure instead of hiding the plant where it cannot do much.

Practical Recommendation

For most keepers, a tougher or better-matched plant is the smarter choice. If you still try it, test with a small amount first and be ready to move the plant before it is badly damaged.

The decision should center on this signal: Electric Blue Johannii is likely to chew or tear this plant before it settles in.

Best Use Case

Water Fern is usually the wrong plant for Electric Blue Johannii if your goal is a stable display tank. The issue is rarely one dramatic failure on day one; it is the steady mismatch between what the fish does in the scape and what the plant needs to stay attractive long term.

Frequently Asked Questions About Water Fern and Electric Blue Johannii

Is Water Fern a good plant for Electric Blue Johannii?

Water Fern is not recommended for Electric Blue Johannii. The issue is practical, not cosmetic: electric Blue Johannii is likely to chew or tear this plant before it settles in.

Can Electric Blue Johannii damage Water Fern?

Electric Blue Johannii is likely to chew or tear this plant before it settles in.

Do Water Fern and Electric Blue Johannii share the same water conditions?

Water Fern and Electric Blue Johannii share a workable water window around 24 to 28 °C, pH 7.8 to 8, and 10 to 15 dGH. Keep the tank near the middle of that overlap for the best long-term result.

What does Water Fern add to a tank with Electric Blue Johannii?

Its structure adds useful refuge value beyond the normal visual role of the plant.

What is the main risk in this plant and fish pairing?

Electric Blue Johannii is likely to chew or tear this plant before it settles in.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

Other Fish for Water Fern

Other Plants for Electric Blue Johannii