hi guys thankyou for all of this, i have managed to take back my elephant nose pangasius and clown loaches today will this help me
?? wat are parameters? why cycle??? what is this?
no problem, glad you've taken the fish back, that's a good start. I suspected you hadn't been told any of this, i wrote up this beginners guide to cycling and water quality a little while ago. let me know if you've any more questions afterwards!
Water Chemistry - The Basics
We are not fish keepers, we are water keepers, keep your water happy and your fish will be happy.
When your researching and asking questions you'll quite often see people asking for your water stats and asking how you've cycled your tank, this brief guide explains why they need to know this information, and therefore why you need to know it.
The absolute first thing you should buy when your keeping fish is a water test kit. I recommend the API Fresh Water Master Test Kit, they're readily available (in the UK), fairly cheap, easy to use and quite accurate (lots of test kits are awful!)
The main things you'll need to test for are ph, ammonia, nitrite and nitrate. This gives you an indication of the health of your tank it's mostly related to the nitrogen cycle often refereed to as cycling.
Your fish create ammonia in their waste, this is toxic so it must be removed from the water, this is what your filter is for, there is nitrifying bacteria living in there who convert the ammonia into nitrite (also toxic) then to nitrate which is much safer, you keep this at a manageable level through doing water changes every week.
The main problem with new fishtanks is that the filter's don't come with the bacteria you need. they can't live out of water in the sponge on the shelf in the fish store, however they are all around us, and will relish the opportunity to grow and develop when they find a nice safe home (your filter) and a source of food (fishy waste). The problem starts becuase when you add fish to your tank you will have a very very small amount of bacteria, they take a while to grow and multiply to the point where they can eat all the waste from your fish, so for the first few weeks of putting fish in the tank the bacteria are growing and will struggle to keep up, so you get toxic levels of ammonia and nitrite in your tank, this can lead to death or disease.
In the past this was always countered by putting in some very hardy fish at first and hoping that they would survive the toxic levels, then when the bacteria had built up after a few weeks you could add more sensitive fish. However this really wasn't very fair on the poor fish who had to start the tank off, I dread to think how many will have died.
so in the last 3/4 years a new technique called fishless cycling has developed, this is where you add pure ammonia to the tank to grow the bacteria on until they are at a point they can handle the fishes waste, and then you add your fish when it's safe for them. this is detailed in a pinned topic here, have a read.
so that should tell you why the first thing you need is a test kit. if you don't know what level of ammonia, nitrite, or nitrate you have in your tank, you don't know if you have enough bacteria to keep the tank going or if you need to do anything else.
Now I know that's a fair bit to take in but it should be your starting point. so digest all that and let us know what your water test readings are, then we'll tell you what the next step is and what fish could be suitable for your tank.