Why Do Water Changes? And Stocking Question

[lacy]

Hello, I have had my 20 gallon tank set up for a couple months now. Just looking thru this website I have realized i have not been looking after my tank quite right. I have a few questions. The first is why do I have to do a water change and every how often should i do it? I thought you had to get a culture going of the good bacteria or the fish will die. Wont changing the water kill my fish cuz i am taking all the good bacteria out?. And when i change it do I have to add the stuff to the water that makes it safe for the fish again if i use dechlorinated water? Another question i have is what is cycling? I have heard of fishless cycling and cycling with hardy fish, i just dont know what this is. And last but not least I went out and bought a 33 gallon tank cuz it was on sale and i couldn't resist. I was just wondering what stocking options i have. I like oscars and parrot fish, but i also like sharks and catfish. And i was thinking of a few loaches. But i dont know if any of these will live together peacefully. I would be gratful for any ideas

 

[djloach]

Hello, I have had my 20 gallon tank set up for a couple months now. Just looking thru this website I have realized i have not been looking after my tank quite right. I have a few questions. The first is why do I have to do a water change and every how often should i do it? I thought you had to get a culture going of the good bacteria or the fish will die. Wont changing the water kill my fish cuz i am taking all the good bacteria out?. And when i change it do I have to add the stuff to the water that makes it safe for the fish again if i use dechlorinated water? Another question i have is what is cycling? I have heard of fishless cycling and cycling with hardy fish, i just dont know what this is. And last but not least I went out and bought a 33 gallon tank cuz it was on sale and i couldn't resist. I was just wondering what stocking options i have. I like oscars and parrot fish, but i also like sharks and catfish. And i was thinking of a few loaches. But i dont know if any of these will live together peacefully. I would be gratful for any ideas

Most of the good bacteria lives in the filter. Some will also live in the gravel and on plants, driftwood, rocks and other ornaments and a very tiny amount will live in the water. So little that it won't matter if you changed 90% of the water there will still be lots of good bacteria around.

The fish, rotting left over food, rotting leaves and other stuff create ammonia. Ammonia is toxic to fish. The bacteria convert ammonia to nitrites. Nitrites is also toxic to fish so another type of bacteria converts nitrites to nitrates. Nitrates isn't near as toxic to fish as ammonia or nitrite but it isn't good for fish in high concentrations either. Unfortunately if nitrates build up too high the only way to get rid of it is through a water change. Ideally you would like your nitrates to be below 25ppm but most fish can tolerate nitrates higher than that.

Another reason for doing a water change is that you can 'vacuum' your gravel/substrate at the same time keeping your tank cleaner and a nicer place to live for the fish as well as more appealing for you to look at.

Some people do smaller water changes more often, others do larger water changes less often. A lot depends on you and your tank and how quickly nitrates build up. I change about 20% of the water once a week and that is probably a reasonable starting point.

There is another way to get rid of nitrates and that is to have lots of plants. Plants will use the nitrates and a well planted tank with lots of fast growing plants will often not accumulate nitrates. But I would still reccommend changing the water regularly to keep it fresh (who knows what other toxins might build up unknowlingly) and to vacuum the substrate.

 

[sparklefuzz]

I went out and bought a 33 gallon tank cuz it was on sale and i couldn't resist. I was just wondering what stocking options i have. I like oscars and parrot fish, but i also like sharks and catfish. And i was thinking of a few loaches. But i dont know if any of these will live together peacefully. I would be gratful for any ideas

I have a 40g tank and had to rehome parrots and oscars because they simply get too big for the tank. I've also been told that clown loaches would grow too big for a 40g, but I'm not sure on other loaches. Sharks also get pretty big, but it would depend which you were looking at. I'm sure catfish would be fine. As for who gets along, I'm sure another more knowledgable member will help you out on that. In the meantime, there's lots of FAQ's threads pinned with fabulous information, and also if you google each fish name you'd like to keep, or go to the fish index here, you'll find out recommended tank sizes and tank mates for each species. have fun!

 

[The-Wolf]

try thinking of the tank like a fizzy pop bottle.
eventually the fizz will dissipate if the lid is not put back on.

when doing a water change you are putting far more than just water back into the tank, there are base elements and minerals disolved in it and aquatic life need these just as much as the water it's self.
also by doing a partial water change you are taking some of the waste out, much like a river would send it to the sea.

HTH

 

[Bex]

I think I've read that 1 Oscar needs a minimum tank size of 75 gallons. I'm not sure about Parrot fish but I think they are quite big also - and big fish tend to be big poopers!

If the sharks you like are silver sharks then, again, they need a big tank because they get big and they are very fast swimmers so need lots of room. They need at least a 5ft to 6ft long tank as they can get up to 1ft!!!

Hope this helps!

 

[lacy]

Thanks everyone for the info on why to change water, I understand how important it is now.As for the oscars and parrotfish, i guess i will have to rethink my stocking ideas.