Can Freshwater Flounder and Tiger Shrimp Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Freshwater Flounder and Tiger Shrimp are not recommended as tank mates due to incompatible water types and conflicting pH requirements and incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Freshwater Flounder

Trinectes maculatus

Tiger Shrimp

Caridina mariae

🐠Family Group
Freshwater Flounder
Oddballs
Tiger Shrimp
Invertebrates
Temperament
Freshwater Flounder
Peaceful (2/10)
Tiger Shrimp
Peaceful (0/10)
Temperature
✓ Compatible
Freshwater Flounder
20–26°C
Tiger Shrimp
20–25°C
pH Range
✗ No overlap
Freshwater Flounder
7.5–8.5
Tiger Shrimp
6–7.4
Hardness (dGH)
✗ No overlap
Freshwater Flounder
10–25
Tiger Shrimp
4–8
Water Type
✗ No overlap
Freshwater Flounder
Brackish Required
Tiger Shrimp
Freshwater Only
Flow Preference
✓ Compatible
Freshwater Flounder
Moderate
Tiger Shrimp
Low
Min Tank Volume
Combined: 110 L
Freshwater Flounder
110 L
Tiger Shrimp
19 L
Swimming Level
Shared: 1 zone
Freshwater Flounder
Bottom
Tiger Shrimp
BottomMiddle
🏷️Behavior Tags
Freshwater Flounder
NocturnalDigger (Disturbs Substrate)Shy / Slow Moving (Easily Stressed)Shrimp EaterFry Predator
Tiger Shrimp
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Freshwater Flounder and Tiger Shrimp?

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.

Freshwater Flounder
Tiger Shrimp
Test both in my tank

Behaviour & Temperament

Freshwater Flounder is a peaceful species (2/10), while Tiger Shrimp is peaceful (0/10). This modest difference means Freshwater Flounder may occasionally assert dominance over Tiger Shrimp.

Freshwater Flounder and Tiger Shrimp 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.

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: Freshwater Flounder is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

Water Parameters

The safe temperature window for both species falls between 20°C and 25°C. Aim for the midpoint of this range (around 22.5°C) for optimal comfort.

The pH requirements of Freshwater Flounder (7.5–8.5) and Tiger Shrimp (6–7.4) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Freshwater Flounder needs 10–25 dGH while Tiger Shrimp requires 4–8 dGH.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Freshwater Flounder and Tiger Shrimp together, plan for an aquarium of at least 110 litres with a minimum length of 90 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), Established Algae (Otocinclus), Plants - Densely covered, Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

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

Why This Pairing Usually Fails in Practice

Freshwater Flounder and Tiger Shrimp 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Freshwater Flounder and Tiger Shrimp.

Show 10 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Freshwater Flounder is a known shrimp eater and may prey on small invertebrates or nano fish like Tiger Shrimp.

Frequently Asked Questions

Can Freshwater Flounder and Tiger Shrimp live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Freshwater Flounder and Tiger Shrimp need?

A minimum of 110 litres (tank length at least 90 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 Freshwater Flounder and Tiger Shrimp together?

Keep the aquarium between 20°C and 25°C. A target of around 22.5°C sits comfortably within both species' preferred ranges.

Are Freshwater Flounder or Tiger Shrimp aggressive?

Freshwater Flounder is peaceful (2/10) and Tiger Shrimp is peaceful (0/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Freshwater Flounder and Tiger Shrimp need?

Their pH requirements do not overlap. Freshwater Flounder prefers 7.5–8.5, while Tiger Shrimp needs 6–7.4. This makes them incompatible in the same water chemistry.

Does Freshwater Flounder being nocturnal affect compatibility?

Freshwater Flounder is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Freshwater Flounder during evening hours.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
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