The Narragansett Kelp Sanctuary

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The Narragansett Kelp Sanctuary

"Bring the rugged, majestic beauty of the Newport coast directly into your foyer. This isn't just an aquarium; it's a living piece of the Atlantic. The deep greens of the sugar kelp and the playful movement of native Cunners create an atmosphere of coastal authenticity that perfectly complements the weathered cedar and navy accents of a high-end beach house."

Minimum Tank Size

Standard 120g (48x24x24) with double-paned insulated glass

Volume

120 gal

Water Parameters

50°F-65°F

8-8.2 pH

Substrate

Coarse grey beach gravelCrushed oyster shells

Hardscape Components

Local Narragansett GraniteSloping from back-left to front-center to mimic a rocky jetty

Fauna Inventory

Cunner (Tautogolabrus adspersus)

Wrasse

Middle water column

Northern Star Coral (Astrangia poculata)

Ahermatypic Coral

Lower hardscape

Atlantic Blue-legged Hermit Crab (Pagurus sp.)

Invertebrate

15x

Substrate dweller

Flora Inventory

Sugar Kelp (Saccharina latissima)

Macroalgae

4 large blades

Center background

Sea Lettuce (Ulva lactuca)

Macroalgae

6 clumps

Foreground rocks

Dead Man's Fingers (Codium fragile)

Macroalgae

2 large specimens

Midground right

The Narragansett Kelp Sanctuary

Biotope Aquascape Plan

aquascaping.ai

January 15, 2026

TankStandard 120g (48x24x24) with double-paned insulated glass (120 gal)

Parameters50-65°F • pH 8-8.2

DifficultyAdvanced

Fauna

3x Cunner (Tautogolabrus adspersus)
5x Northern Star Coral (Astrangia poculata)
15x Atlantic Blue-legged Hermit Crab (Pagurus sp.)

Flora

4 large blades Sugar Kelp (Saccharina latissima)
6 clumps Sea Lettuce (Ulva lactuca)
2 large specimens Dead Man's Fingers (Codium fragile)

Shopping List

Tank & Supplies

Item	Qty	Est. Cost
120 Gallon Double-Paned Insulated Glass Aquarium- Custom insulated glass is critical for preventing condensation in a coldwater setup.	1 unit	$2,800.00
1HP High-Efficiency Aquarium Chiller- Overpowered for 120g to ensure efficiency and quiet operation in a foyer.	1 unit	$1,450.00
Insulated PVC Plumbing Kit- Prevents sweating and temperature loss in the cabinet.	1 set	$150.00
Gyre Flow Pumps (Tidal Simulation)- Essential for mimic tidal movement required by Sugar Kelp.	2 units	$600.00
Full Spectrum LED Fixture (6500K focus)- Focus on daylight spectrum to support macroalgae growth.	1 unit	$450.00
Coarse Grey Beach Gravel- Provides a naturalistic New England coastal substrate look.	80 lbs	$120.00
Crushed Oyster Shells- Mix with gravel for texture and minor pH buffering.	20 lbs	$40.00

Hardscape

	Item	Qty	Est. Cost
	Local Narragansett Granite Blocks- Sourced or purchased stones to create the 'jetty' look; must be cured before use.	180 lbs	$250.00

Flora

Item	Qty	Est. Cost
Sugar Kelp (Saccharina latissima)- Centerpiece macroalgae; ensure anchors are secure on granite.	4 large blades	$160.00
Sea Lettuce (Ulva lactuca)- Tuck into rock crevices in the foreground.	6 clumps	$60.00
Dead Man's Fingers (Codium fragile)- Distinctive architectural midground elements.	2 large specimens	$90.00

Fauna

Item	Qty	Est. Cost
Cunner (Tautogolabrus adspersus)- Hardy native fish; ensure rockwork has adequate hiding spots.	3	$120.00
Northern Star Coral (Astrangia poculata)- Non-photosynthetic; place in lower flow areas of the hardscape.	5	$200.00
Atlantic Blue-legged Hermit Crab- Crucial clean-up crew for coldwater systems.	15	$75.00

Setup Guide

Coldwater Infrastructure

Day 1

Position the 120-gallon insulated glass tank in its final location in the foyer, ensuring the floor can support the weight.
Apply high-density foam insulation to the back and sides of the tank to prevent condensation and improve chiller efficiency.
Install the 1HP High-Efficiency Chiller and plumb it using insulated PVC piping to prevent 'sweating' and energy loss.
Set up the Gyre flow pumps to create a unidirectional tidal surge across the length of the tank.

Tip: Because this is a coldwater system, insulation is critical to prevent puddles of condensation from forming on your flooring.

The Narragansett Jetty

Day 2

Rinse the coarse grey beach gravel and crushed oyster shells thoroughly and layer them 2-3 inches deep.
Scrub the local Narragansett Granite to remove loose debris and stack it in a sloping formation from the back-left corner toward the front-center.
Ensure the granite structure includes multiple deep crevices and overhangs for the Cunners to use as sleeping quarters.

Tip: Place larger granite pieces directly on the tank bottom before adding substrate to prevent the crabs from undermining the structure.

Coldwater Biological Cycle

Week 1-3

Fill the tank with RODI water and mix high-quality marine salt to a specific gravity of 1.025.
Set the chiller to a steady 55°F and begin the nitrogen cycle by 'ghost feeding' or using a bottled bacteria starter.
Monitor ammonia, nitrite, and nitrate levels every three days.

Tip: Nitrifying bacteria work significantly slower in 55°F water compared to tropical systems; be patient as the cycle may take up to three weeks.

Macroalgae Forestation

Week 4

Secure the Sugar Kelp holdfasts to the granite in the center background using aquarium-safe gel or fishing line.
Tuck clumps of Sea Lettuce into the foreground rock crevices where flow is moderate.
Position Dead Man's Fingers in the midground right, ensuring they have plenty of space for their branching growth.

Tip: Ensure your LED lights are set to a 6500K spectrum to mimic the shallow coastal light found in RI waters.

Cleaners & Coldwater Corals

Week 6

Drip-acclimate the 15 Atlantic Blue-legged Hermit Crabs over 90 minutes to match the tank's salinity and 55°F temperature.
Place the Northern Star Corals on the lower granite faces in areas of high flow but low light.
Begin spot-feeding the corals with baby brine shrimp twice weekly.

Tip: Northern Star Coral is non-photosynthetic and relies entirely on regular feedings to thrive in the absence of high-intensity reef lighting.

Introducing the Cunner

Week 10+

Source 3 Cunners through professional suppliers or legal local collection with a RI Saltwater License.
Complete a mandatory 30-day quarantine in a separate chilled system to ensure they are parasite-free.
Transfer the Cunners to the display tank using a long drip-acclimation process.
Observe for territorial behavior as they establish their homes within the granite crevices.

Tip: Cunners are curious and may 'inspect' your hand during maintenance; they are hardy but sensitive to sudden temperature spikes above 70°F.

Maintenance Schedule

Daily

Temperature and Chiller Verification

Verify the 1HP chiller is operational and maintaining a stable temperature between 50°F and 60°F. Observe the double-paned glass for any condensation signs that might indicate a seal breach.

Targeted Feeding Schedule

Feed Cunners high-quality marine pellets or frozen mysis. Spot-feed the Northern Star Corals using a pipette with baby brine shrimp or specialized plankton to ensure health in the non-photosynthetic environment.

Weekly

Macroalgae Inspection and Maintenance

Inspect Sugar Kelp blades for attachment to granite. Prune fast-growing Sea Lettuce to maintain aesthetics and prevent it from clogging gyre pump intakes. Remove any decaying matter to keep nutrient levels low.

Water Chemistry and Salinity Check

Test salinity levels and adjust for evaporation using RO/DI water. Monitor nitrates and phosphates to manage the nutrient export from the heavy macroalgae load.

Monthly

Substantial Water Exchange

Perform a 15-20% water change using pre-chilled saltwater (match to 55°F). Vacuum the coarse grey beach gravel to remove detritus trapped between the granite rocks.

Chiller and Gyre Pump Servicing

Clean the chiller air filter to ensure maximum efficiency. Inspect and clean the gyre flow pumps to ensure the high-velocity tidal simulation required by the Sugar Kelp remains consistent.

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