its a filter media- its purous ceramic usually in tube form- do not confuse with plastic stuff that is on the market- filter media is all about surface area- the more you have the more bacteria you can colonise- bacteria help breakdown pollutants in the water helping water quality.
i guess not :)
Dont go with brands that have not been recomended.
Dennerle/dupla/sera- all german companies, where the european style of CO2 tanks were born.
ADA the best no doubt, but very expensive. Japanese company the best from the asia style of planting.
If you cant go with those companies- then try and do without until you have researched brands available to you. If you dont want to spend money on the high quality products then you dont want the high quality results they produce.
is it ok that i have taken out the carbon from my juwel filter and added the fertiliser but i left the other sponges , like the blue ones because i cannot remember what them ones are for if anyone know can they tell me whether i should leave them in or take them out.
sponges are mechanical and biological- which is why they are not the best media- you cannot have it both. Carbon removes chemicals from the water, its basically what is in a britta water filter cartridge or any water filter cartridge.
The other sponge layer swill not affect the fert.
Dose 1 cap full per 5gallon of fresh water.