View Full Version : So many water changes!

08-26-2006, 07:14 AM
Hello All,
With so many companies, mags, online forums offering aquatic advice, sometimes it doesn't make sense why i'm adviced to make so many frequent water changes(ie 3 x 25% weekly ). I understand the fresher the water the better the quality. But doesn't that disrupt the bio filter in any way?

08-26-2006, 07:16 AM
25%- 3 times a week?
How big is your tank & what are you keeping in it?

08-26-2006, 07:22 AM
Hello Jennigypsy,
My tank is 55gal w/ a variety of malawis, the 3x25% comment is a common suggestion to other i keep noticing on forums, magazines etc etc. I only do a 25-30% a week on all my tanks depending on nitrate count. See my signature for the fish i keep

08-26-2006, 08:21 AM
oh---that 1st 55 gal...is well...way overstocked. You've got severums in with africans, in with pike cichlids, with barbs......
the quantity of fish in that tnk may be the reason for the 3x weekly suggestions.....
Usually (and I stress USUALLY) 1-30% water change per week is enough.

08-26-2006, 10:19 AM
yeah i know it's a tad overstock, the loach is a juvi that's already in my other 55gal, i'm in the process of moving the severums to my community tank soon, as well as the lonely barb. I'm still debating about moving the Convict. All of my fish range from 1-2.5" right now(and planning to accomedate for their adult size) and the nitrate level is low from the weekly water changes.
It sounds like a lot of fish, but honestly w/ their current size all is fine.

08-26-2006, 10:55 AM
not too sure where those convicts & pike are going to fit in those set ups....sure they may be small but aggressive fish are aggresive fish...why wait until they start killing to change the set up?

im doing water changes that frequently on a 70 gallon tank trying to cure HITH disease...you should only be doing water changes to remove nitrates...therefore how often someone does water changes on a 10 gallon tank with one fish with differ very much so than a fully stocked large fish tank....more people recommend keeping nitrates below 40 ppm....so however often that occurs on your tank, that means you should do a water change

being overstocked and under filtered will effect this too. what type of filtration are you running?

08-26-2006, 11:52 AM
Hello ATG204,
Perfectly understood, which is why I'm already making plans to accomedate for their adult size. As far as for filtration, i'm running an xp3 w/ an emperor 400. Nitrate build up ranges from 20-30ppm depending on how often i feed.

08-26-2006, 04:00 PM
You want real advice on water changes?

You need to figure the answer for yourself as there are so many pieces of the puzzle that only you know.

Figure out what you feel is a safe level of nitrates and do what is required to keep teh tank below that level.

Crude example follows:
If I have a 100 gallon tank, 100 ppm of nitrate is my chosen limit and my system produces 25 ppm of nitrates per day I would probably choose to do a 50% change every other day.

08-27-2006, 12:10 AM
they type of fish you're keeping will dictate how high your nitrates can go as well. oscars can't take the high levels as they will develop HITH, i wouldn't worry about keeping a Dempsey in a tank with higher levels of nitrates

filtration sounds good though so maybe hold back a bit on the feeding and thin the fish out a bit, you'll see the nitrates drop for sure.

08-27-2006, 05:28 AM
Another thing to consider is with more fish comes more waste. Also with larger fish and certain species. In my 55g, I siphon the poop off the bottom every other day, just a 5 gallon buckets worth. It takes 5 minutes. Considering the substrate and wood, thats a 10% change 3 times a week and I could probably get away with less. Since you have so many fish in there, you're probably right on track. It's a lot less work in a 55g than a 150 or 200g+ tank.