Pleco Wafers 100g

The wafers are 16mm across, which is wider than most of the isopods that will end up sitting on one. It matters more than it sounds. A wafer that holds its shape when damp does not disappear into the substrate overnight, so a colony can work at the same piece for two or three days and anything left over lifts out clean.

These started life as a sinking food for bottom-feeding fish, which is where the density and the shape come from. Knowing that explains what they do well in an invertebrate enclosure and where the sensible limits sit.

What is in them

Herring meal and soya carry the protein. Wheat and potato bind the wafer and give it the slow-softening texture. Then the plant matter: spirulina, mycoprotein, alfalfa and spinach.

The additive list is longer than most foods aimed at this hobby. Vitamins A, D3, E and C, a mineral premix covering iron, zinc, copper, manganese and iodine, then lysine, betaine, beta-glucan, L-carnitine and omega-3 oils.

Composition runs to 47.4% crude protein, 4% oils and fats, 3% fibre, 7.9% ash and 8% moisture.

They also contain colourants. Those are in the formula for the aquarium market and do nothing for a woodlouse. I would sooner print that than trim the ingredient list down to the flattering parts.

Protein is a frequency question

Forty-seven per cent is high, and the hobby tends to react to that number in one of two unhelpful ways: treat the food as dangerous, or tip it in daily because the isopods clearly like it.

Neither is right. Protein does not poison a colony. What it does is sit uneaten if you put too much in, and uneaten protein in a warm damp box is how you end up with a grain mite bloom or a fungus gnat problem. The fix is portion size and interval, not avoidance.

Leaf litter and decaying wood stay the base of the enclosure. The wafers go on top of that as a supplement.

How I feed them

On my shelves a mixed Porcellio tub gets a broken quarter-wafer once or twice a week, put down on a piece of bark or an upturned bottle cap so it stays off the wet substrate. Anything untouched after two days comes out.

Cubaris take less and take it slower. Springtails will find a wafer within hours and graze the surface of it, which is useful if you are running them as a cleanup crew, though it does mean the isopods get less of the wafer than you would assume.

Dampening one before it goes in speeds the whole thing up. Dry, it takes a colony a while to start. A brief dip softens the edges and it gets found faster.

Feed less in the winter, or whenever a tub is cooler and the animals have slowed down. At 21 to 26°C a colony works through a quarter-wafer briskly. Below that they will not, and the leftovers are the problem.

What else takes them

Millipedes will eat them, with less enthusiasm than isopods, and they want calcium and rotting wood more. Darkling beetle larvae and roach colonies clear them fast. The original audience still holds too, so if you keep plecos, corydoras, loaches, shrimp or crayfish alongside the invertebrate shelf, the wafers do the job they were designed for.

Storage

Keep the bag sealed, dry and out of direct sun. Moisture is the thing to watch, because a wafer that takes up damp in the packet will go mouldy in the packet. 100g is a long run of feeds for a shelf of isopod tubs, so this is being stored for months, not weeks.