Aquarium Fish
Buy and sell aquarium heaters, pumps and small tank kit in Costa Rica.
The heater that held a tank steady through cool nights in San Ramón is often more than a warm room in Nicoya needs, where the water wants a fan across it instead. Thermometers, air pumps, nets and the bags and boxes used to move a tank make up the rest of the small kit, and most of it outlasts the tank it came with. New and pre-owned pieces both belong, and used ones make most sense as a lot when a tank comes down. Say what size tank each piece ran on, because that is how the next owner knows whether it fits.
Heaters for a tank in a cool highland house:
in San Ramón or Tres Ríos the room cools at night and an unheated tropical tank cools with it. Glass heaters are the cheap, common kind, either preset or with a dial. Titanium heaters will not shatter if knocked and pair with a separate controller that cuts the power if the water runs warm. A plastic guard keeps a glass heater off the tank wall. Size a heater by the gap between the coldest night in the room and the water you want, not by the tank volume on the box. Beyond a desktop tank, a pair of smaller heaters at opposite ends is safer than one large one: heaters usually fail stuck on, half the power warms the water far more slowly, and if one dies the other stops the temperature crashing. The tanks, filters and lights themselves are in aquariums and aquarium accessories.
Thermometers, fans and air pumps for a warm room on the coast:
a heater dial is a guess, and stick-on strips read the room as much as the water, so trust a glass or probe thermometer inside the tank. In Nicoya or Jacó the trouble is heat: a tank in a closed room or by a sunny window climbs through the afternoon, and a clip-on fan across the surface cools it by evaporation, at the cost of topping up more often. Warm water holds less oxygen, which is where an air pump and airstone earn their place. A check valve on the airline stops water siphoning back into the pump when the power drops, and a battery air pump covers outages and moving day. Pumps sized for outdoor water sit with the pond gear.
Nets, breather bags and insulated boxes for moving a tank:
the drive between the coast and the Central Valley is where a move goes wrong, because water in a bag changes temperature far faster than water in a tank. A polystyrene box or a cooler keeps it steady, with a towel to stop the bags rolling. Breather bags let oxygen through the plastic and cope with long trips better than a knotted bag with air on top, and a fine, soft net snags fins less than a coarse one.
A used heater, air pump or feeder on test:
run a second-hand heater overnight in a bucket beside a thermometer you trust, and compare where the water settles with what the dial says. A small offset is harmless once you know it; a heater that keeps heating past its setting has the classic fault and belongs in the bin. Check the tube for scorch marks or water inside and the cord for cracking where it enters the cap. An air pump that buzzes loudly and gives weak bubbles has a worn diaphragm, a cheap part that brings most pumps back. On an automatic feeder, look for corrosion in the battery compartment and food caked in the drum. Fish food is only worth taking sealed and in date: once a tub is open, air and damp take the quality out of what is left.
Wattage, dial offset and tank size on a heater listing:
with those filled in, most questions are answered before they are asked. Photograph the label so the wattage and voltage can be read, say what size tank it ran on and whether that was a cool highland room or a warm one on the coast, and send the guard and clips with it. When a whole tank comes down, the small kit goes better as one lot with a list of what is in the box. Unplug a heater and leave it in the water until it has cooled before lifting it out, then pack it inside its guard: a glass heater pulled out hot is the one a buyer in Grecia unwraps cracked.