Can Pacific Sturgeon and Ruby Green Hap Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Pacific Sturgeon and Ruby Green Hap are not recommended as tank mates due to no temperature overlap. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Pacific Sturgeon

Acipenser transmontanus

Ruby Green Hap

Haplochromis sp. 'Ruby Green'

🐠Family Group
Pacific Sturgeon
Oddballs
Ruby Green Hap
Cichlids - African
Temperament
Pacific Sturgeon
Mostly Peaceful (3/10)
Ruby Green Hap
Aggressive (7/10)
Temperature
✗ No overlap
Pacific Sturgeon
10–22°C
Ruby Green Hap
24–28°C
pH Range
✓ Compatible
Pacific Sturgeon
6.5–8
Ruby Green Hap
7.5–8.6
Hardness (dGH)
✓ Compatible
Pacific Sturgeon
4–20
Ruby Green Hap
10–20
Water Type
✓ Compatible
Pacific Sturgeon
Brackish Tolerant
Ruby Green Hap
Freshwater Only
Flow Preference
✓ Compatible
Pacific Sturgeon
High
Ruby Green Hap
Moderate
Min Tank Volume
Combined: 20000 L
Pacific Sturgeon
20000 L
Ruby Green Hap
150 L
Swimming Level
Shared: 1 zone
Pacific Sturgeon
Bottom
Ruby Green Hap
MiddleBottom
🏷️Behavior Tags
Pacific Sturgeon
Piscivore (Eats small/nano fish)Digger (Disturbs Substrate)Hyperactive / Fast SwimmerShrimp EaterSnail EaterAggressive Eater (Starves shy fish)
Ruby Green Hap
Aggressive to same species/look-alikesTerritorial (Defends specific area)Hyperactive / Fast SwimmerDigger (Disturbs Substrate)Fry Predator
Stocking calculator

Can your tank handle Pacific Sturgeon and Ruby Green Hap?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Pacific Sturgeon
Ruby Green Hap
Test both in my tank

Behaviour & Temperament

Pacific Sturgeon is a generally mild-mannered species (3/10), while Ruby Green Hap is semi-aggressive (7/10). This notable difference means Ruby Green Hap may occasionally assert dominance over Pacific Sturgeon.

Pacific Sturgeon and Ruby Green Hap both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Water Parameters

There is no temperature overlap between Pacific Sturgeon (10–22°C) and Ruby Green Hap (24–28°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 7.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Pacific Sturgeon and Ruby Green Hap together, plan for an aquarium of at least 20000 litres with a minimum length of 600 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Both species do well with high (river/stream) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Usually Fails in Practice

Pacific Sturgeon and Ruby Green Hap are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Frequently Asked Questions

Can Pacific Sturgeon and Ruby Green Hap live together?

No. This combination is not recommended. Key incompatibilities — such as non-overlapping temperature ranges — make cohabitation unsafe.

What size tank do Pacific Sturgeon and Ruby Green Hap need?

A minimum of 20000 litres (tank length at least 600 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Pacific Sturgeon and Ruby Green Hap together?

Unfortunately, there is no temperature range that satisfies both species. Pacific Sturgeon requires 10–22°C, while Ruby Green Hap needs 24–28°C.

Are Pacific Sturgeon or Ruby Green Hap aggressive?

Pacific Sturgeon is generally mild-mannered (3/10) and Ruby Green Hap is semi-aggressive (7/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Pacific Sturgeon and Ruby Green Hap need?

Both species overlap in the 7.5–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Ruby Green Hap's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Ruby Green Hap space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 7, 2026
Last updated
May 7, 2026
Issues or corrections?
Contact the editorial team

Related Comparisons