Matching Particle Size to Mouth Size: A Guide to Target Feeding Corals and Fish

A lot of coral and fish feeding failures come down to one simple mismatch: the food is the wrong size or shape for the mouth it is meant to feed. A large-polyp coral will happily grab a chunk of mysis. A small-polyp SPS colony cannot. A powerful reef fish will inhale flake in a heartbeat, but a shy mandarin needs something tiny and slow moving. Getting particle size right is the difference between food that actually gets eaten and food that just dissolves into your water column, feeding algae instead of your animals.

Start with the mouth, not the bag

Before buying any prepared food, look closely at what you are trying to feed. Large polyp stony corals such as Euphyllia, Trachyphyllia and Duncans have tentacles and mouths that can handle whole pieces a few millimetres across. That is exactly the niche Hikari Coralific Delite sits in. It is a soft, moist prepared food cut to a size that these corals can wrap tentacles around and physically ingest, not just absorb. Feed it with a turkey baster or feeding tube directly onto an open polyp during low flow periods, ideally with return pumps paused briefly so the food is not blasted away before the coral responds.

Small polyp stony corals are a different game entirely. Acropora, Montipora and similar SPS have tiny polyps and rely far more on capturing suspended particulates and dissolved organics than grabbing discrete chunks. Vitalis SPS Coral Food is formulated at a much finer particle size specifically for this feeding style, designed to be broadcast over the tank so polyps can extend and filter it from the water. Watch a healthy SPS colony after a broadcast feed and you will often see polyps fully extend and take on a fuzzier, more textured look within ten to fifteen minutes as tentacles reach out to sweep particulate from the passing current.

Broadcast feeding for mixed reefs

Most display tanks hold a mix of coral types plus fish, which is where a broadcast food like Reef Roids earns its place. It is a fine, protein-rich powder that you mix with tank water into a slurry and pour or squirt into an area of low flow, letting it settle over LPS and softies while finer particles drift to SPS branches. Because it clouds the water briefly, it also functions as a general feeding event that fish will investigate, so it does double duty in a mixed system without you needing three different feeding sessions back to back.

Fish feeding: flakes, brine and everything in between

Fish feeding is more forgiving on size but temperament still matters. Fast, confident swimmers like damsels and clownfish will out-compete shier fish at the surface, so Ocean Nutrition Brine Shrimp Plus Flakes works best fed in two or three small pinches scattered across different parts of the tank rather than one big dump in one spot. This spreads feeding pressure and gives slower or more cautious fish, including some wrasses and gobies, a fair shot at getting fed before the flake disintegrates.

A practical feeding rhythm

• LPS corals (Coralific Delite): target feed two to three times a week, directly onto extended polyps.
• SPS corals (Vitalis SPS Food): broadcast daily to every second day in small amounts, better little and often than one large feed.
• Mixed reef broadcast (Reef Roids): two to three times weekly, timed with reduced flow.
• Fish flake (Ocean Nutrition Brine Shrimp Plus): daily, split into two feeds, only what clears in under two minutes.

Overfeeding any of these shows up fast as cloudy water, oily film on the surface, or a spike in nuisance algae within a week or two, so it pays to feed conservatively and adjust upward if colour and polyp extension are not improving.

We stock a range of Hikari, Vitalis, Reef Roids and Ocean Nutrition foods for exactly this kind of targeted feeding, though what is on the shelf shifts with demand and season. Take a look through our current range and check out our stock list before you plan your feeding routine, and if you are building out a broader Vitalis-based feeding regime it is worth browsing the full range on the Vitalis collection page. For general reef husbandry gear to pair with your feeding schedule, our marine aquarium collection and the wider Hikari range are good places to keep browsing.