Blue Maxima Clam (Tridacna maxima)

The Blue Maxima Clam (Tridacna maxima) is an aquacultured, first grade giant clam with a mantle in blues and turquoise, patterned in the stripes, spots, and wavy lines that make maximas the most colorful clams on the reef. Aquacultured clams are raised on farms instead of being harvested from wild reefs, and they arrive used to captive life. This is a young clam, which makes it an affordable way to start a clam garden and watch it color up and grow in your own tank. Browse the rest of our corals, anemones, and clams and our saltwater livestock and supplies.

First grade or ultra? First grade clams show solid blue and turquoise color, often with some brown or less intricate patterning. If you want the most saturated, fully patterned mantle available, step up to our Ultra Grade Maxima Clam. Each clam is an individual, so the exact pattern may differ from the photo.

Care Guide

• Tank: 30 gallons or larger, established and stable, with true reef-grade lighting.
• Lighting: intense. Maximas live high on the reef. Start it midway up the rockwork for the first week or two, then move it higher as it opens fully, so it adjusts to your light instead of bleaching.
• Flow: low to moderate and indirect. The mantle should ripple, not fold.
• Placement: set it on rock, rubble, or a small clam stand where it can grip with its byssal foot. Once attached, do not pry it loose; move the rock instead.
• Feeding: photosynthetic, but clams under about 3 inches get a large share of their nutrition from phytoplankton. Dose live phytoplankton several times a week.
• Water: 76 to 80°F, salinity 1.024 to 1.026, calcium 400 to 450 ppm, alkalinity 8 to 11 dKH, magnesium around 1300 ppm. Test regularly, since a growing clam uses calcium and alkalinity.
• Pest check: look over the shell and the byssal opening every week or two for tiny white pyramid snails and remove any you find. Bristleworms and some crabs can also bother small clams, so keep it on rock above the sand.

Specifications

Compatibility

Maxima clams have no sting and never bother fish, corals, or inverts. They sit happily among corals and alongside clownfish, gobies, chromis, tangs, cleaner shrimp, and snails. Keep them away from known clam pickers such as large angelfish, butterflyfish, triggers, puffers, and some wrasses, and keep stinging corals and wandering anemones from reaching the mantle. For a full clam garden, combine it with the Ultra Grade Crocea Clam and Derasa Clam.

Recommended Foods & Supplies

• Bulldawg Reef Juice Clam Blend, live phytoplankton made for small clams
• Quantum Easy E Calcium and Quantum Easy Z Alkalinity to keep shell-building chemistry steady
• Salifert Calcium Test Kit and Salifert KH/Alkalinity Test Kit
• Salifert Magnesium Test Kit
• Upgrade path: the Ultra Grade Maxima Clam for top-tier color

FAQ

How big is it?
It is a juvenile, roughly 1.5 to 2 inches across the shell. Sizes are approximate, so come see it in store if the exact size matters to you. Maximas grow slowly and can reach about a foot over many years.

What is the difference between first grade and ultra grade?
Grade describes mantle color and pattern. First grade has solid blues and turquoise, sometimes with brown areas or simpler patterning. Ultra grade has the most saturated color and intricate pattern across the whole mantle, at a higher price.

Does a small clam need to be fed?
Yes. Clams under about 3 inches rely on filter feeding much more than adults do. Plan on live phytoplankton several times a week until it grows.

Why aquacultured?
Farm-raised clams take pressure off wild reefs, and they are used to captive conditions. They still need a pest check, since pyramid snails can hitch a ride in any system.

Where should I put it?
On rock or rubble in strong light with gentle flow. Start it partway up and move it higher over a week or two, then let it attach and leave it be.