Water Changes and Nitrates

Brian wrote:
I have a large tank with a light fish load. My nitrates are around
10PPM. Do you need to do a water change with such low nitrates?

When I had a heavier load I would water change enough to keep nitrates
below 40ppm but since my load is lighter the levels of nitrate are
taking much longer to rise.

Brian

You should do water changes no matter what your nitrate levels are. You
could go with a 15% every week or maybe a 25% every 2 weeks.

jake wrote:

Brian wrote:

I have a large tank with a light fish load. My nitrates are around
10PPM. Do you need to do a water change with such low nitrates?

When I had a heavier load I would water change enough to keep nitrates
below 40ppm but since my load is lighter the levels of nitrate are
taking much longer to rise.

Brian


You should do water changes no matter what your nitrate levels are. You
could go with a 15% every week or maybe a 25% every 2 weeks.


I'd say it was proportional to fish load, personally. You can get away
with water changes if your tank is planted. My CO2 injected, planted
tanks rarely need a change of water, only top-up from evaporation
required. The mass of plants act as a natural filter. It works for me.
My shrimp, which are coming up to 18 months, and a pair of Ancistrus
which has just spawned, are thriving in months old water. I have to add
nitrate and phosphate from bottled fertiliser, otherwise the plants suffer.

Nikki