Water Changes - The "correct" way

[kevin007]

My brother has a 20 Gallon fish tank with 2 HOB filters on it. He keeps guppies in the tanks.

Now I tell him that it is important to not change both of the filter cartridge in the HOB because of the beneficial bacteria. He disagrees. Hes been keeping Guppies for around 5-6 years and gets little to no deaths. He does huge water changes when he feels like it (leaves the water overnight to get rid of chlorine) and changes both filter cartridges every time. He also tops up the water when there are evaporation.

Why aren't his fish suffering from mini cycles? Who am I to tell him whats "right" and "wrong" when his fish are healthy and have stayed that way for a couple of years.

He argues that:

1. there are enough beneficial bacteria on the sand/driftwood/ornaments/ filter (excluding cartridge).

2. He has enough guppies so that one or two losses won't make a difference.

3."If it ain't broke, don't fix it"


I'll show him this thread.

 

[cassharper]

1) No. Unless... No
2) I love the argument that smaller animals somehow have less important life than larger ones. If you disregard animal life, then you do. Arowanas do not possess more cognizance of life than guppies
3)It is broke, he just don't know how to tell whether it's broke or not.

Guppies can live in water with temps under 40*F to water with temps over 90*F, needless to say they are prolific. It takes a lot to kill a guppy that doesn't have genetic defects. Just because he can't spot the gill burn with the naked eye, or can't communicate with the fish to find out how much it sucks doesn't mean the fish isn't in adverse conditions.

 

[kevin007]

Well when you have a 100 + guppies, one or two really doesn't make a difference.

Since the fish doesn't have any obvious problems that the naked eye can see, I can't really make an arguement

 

[micstarz]

He isn't doing anything wrong, if the water has been dechlorinated and temperature-matched.

I agree with both you and your brother. There are tons of BB in your tank, but he should only change one filter cartridge at a time, unless his tank has a turf algae filter or is heavily planted.

 

[Pharaoh]

I would go with the changing one filter at a time. No sense in killing the occasional one or two if you don't have too. Gravel will maintain a small amount of bacterial, but not a whole lot.