CO2 drop checker made of high quality glass, use to measure CO2 levels at a glance | Apply to: fish tank, aquarium, especially aquatic plants, tropical fish to watch and cultivate for fish tank. Monitor to be installed below the water surface about 10cm, it is recommended not to install too far from the refiner | Monitoring CO2 levels in your planted aquarium is very important for the health of your plants and fish. Can keep the CO2 levels in your tank consistently by checking it regularly | Easy to install and use: Make sure your test kit is clean. Drop 5 drops of CO2 indicator(not include) into the glass checker and use straw to fill the tank water with the test solution area to 1/2. Then turn the opening facing of drop checker down. Use a sucker to attach it to the side of your tank and wait for up to 2 hours | Indicator color chance shows results: The CO2 indicator (not include) color is blue, when it is blue represented CO2 insufficient; Turns green, the balance of CO2; Turns yellow, means your tank has too much CO2. Make the necessary adjustments and test until you get green

Pre-Filter Sponges made of biochemical sponge,durable,harmless to the water and fish. | High density design,will not block the flow of water into the filter.Easy to connect to the filter and easy to take out to clean. | Size: Height 8cm,diameter 4cm, inner hole diameter 2cm. Sponge cover is single-sided connected onto the water inlet of your filter. Prevent fine debris or particular matter into filter,improved filtering water effect. | Aquarium intake sponges protect small fish and shrimp from getting sucked into the filter intake, it is good for their healthy growth. One end of the sponge is closed. | Note: Suitable for wall-mounted filter inlet and various aquarium product inlets tube size range is from 2.1cm and 2.5cm.