Newbie Question From An Old Hoot

[dimfer]

I have fully established 1360 gallon tank with 11 mature asian arowanas and 2 larger plecos. I feed an average of 3 lbs. of shrimp per week and all my fish seems to be healthy. I used to do 20% water change every other week, which I had been doing religiously for 5 years. I had been busier than usual lately and was not able to do a water change as scheduled. Instead, I checked my water parameters (with relatively new/not expired Nutrafin test kits) tonight.

PH is below 7
ammonia is very light yellow (or zero)
nitrate is very light pink (5 mg/l ).

I grew old on this hobby believing that I have to be doing water change as often as possible.

My question is - based on my test results, my water parameters are ideal and my filters are keeping up with the bioload - can I get away with less frequent waterchange?

How often do big tank owners do waterchange on their tank? And how much?

I would love to find out how often big public aquariums do their waterchange

pls tell me my arowanas will be ok with monthly waterchange
that way, I can help preserving the environment by not unnecessarily throwing away water

 

[BadOleRoss]

I do both weekly water changes and bi-weekly water changes depending on my schedule. My tank, which is only 300 G does fine with both but seems to do just slightly better with the weekly water changes. If you have been doing weekly changes for the last 5 years, I would switch to bi-weekly and monitor the inhabitants and see how they adjust. I don't think I would cut water changes down to monthly....thats a big swing IMO.

 

[dimfer]

tested water on the 3rd week... readings still ok, but changed water anyway.

I hope more people will chime in

 

[Chromobotia]

Is your tank planted? I would think that with 11 Aros in the tank that your Nitrate reading would indicate a water change was necessary well before the 3rd week.

Please let me know your secret for low Nitrate readings.

 

[probe1957]

I have heard people advocate changing tank water only when their nitrate reading gets to 40 ppm. Now maybe 40 isn't a number you're personally comfortable with. Maybe you are more comfortable with 30 ppm. Whatever. I would imagine it would work. I just don't know about a system that leaves little margin for error.

 

[LoganBlade]

I can help preserving the environment by not unnecessarily throwing away water

Why not use it in the garden or on the lawn. No waste that way and I am sure some fertilizer is int eh water for the plants.

 

[carsona246]

I would recommend still doing water changes every 2 weeks or so, but if you get the tank heavily planted that will lower the need to do water changes based off of undesirable parameters. I still think it's a good idea to do regular water changes just to clean things up a bit though

 

[CA-Delta]

I do water changes based completely on water parameters. I think the more efficient your mechanical filtration is at collecting debris and the more dilligent you are at servicing the filter media the longer you can go between water changes. I service the mech. filters every 7 days. My chosen Nitrate target is 20 PPM. I am able to go 10 to 14 days on my 240 and 20 to 30 days on my 100. I will be converting the 240 to the same style of filtration as the 100 soon.

 

[dimfer]

Is your tank planted? I would think that with 11 Aros in the tank that your Nitrate reading would indicate a water change was necessary well before the 3rd week.

Please let me know your secret for low Nitrate readings.

my tank is not planted, I vaccum the bottom of the tank during water change. I also clean my filter box and media when necessary.

 

[dimfer]

I have heard people advocate changing tank water only when their nitrate reading gets to 40 ppm. Now maybe 40 isn't a number you're personally comfortable with. Maybe you are more comfortable with 30 ppm. Whatever. I would imagine it would work. I just don't know about a system that leaves little margin for error.

this basically answered my question. so, there are people doing waterchange based on parameters, not just on the routine. Maybe 40 ppm is pushing it.