# water changes



## argofan (Jul 29, 2015)

hi noob here, i have a newly cycled 20 gal nano tank, fish only with some live rock.
life support is a hob filter with a powerhead for circulation.
i am not running a protein skimmer (I know) for multiple reasons space, money etc.
so i realize that i need to export nitrates through water changes...
my question is,
due to the fact that unlike freshwater, water changes are not free. so when do i pull the trigger on water changes, in my freshwater tanks i try to keep nitrates under 20 ppm. is it the same for saltwater fish only. what about for inverts, what about for soft corals?
thanks in advance for any guidance

i wish you all clear waters my friends

kevin


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## badxgillen (Aug 20, 2010)

The answer to this question can come in a few answers but first you must answer what you are keeping and how well would you like to keep it. If you are doing fish only you can let the nitrates get rather high and not suffer from too many ill effects, some times immune system compromises from prolonged high nitrate exposure. There are some exceptions to this rule with some fishes being able to tolerate extremely high nitrates 80PPM and some fishes that are more sensitive to the higher saturation levels and will suffer when the levels hit around 40PPM.

This last statement is true with many inverts as well, some cannot stand the nitrates and will meet early demises in such systems. In general inverts are much more susceptible to poor water quality and can degrade fast. Most inverts like shrimps,crabs, and anemones will do best when the nitrates are under or around 20PPM

When it comes to corals the differential can be even greater as some corals prefer a modest amount of nitrate in the water around 30-40PPM but most will do best with lower levels around 5-10PPM 

The short answer to your question would most likely be what same maintenance you have mentioned from your previous tanks. Keeping things under 20PPM. The thing is to accomplish this with only water changes could mean biweekly changes or weekly, it really depends on the strain the system can take and the bio load within...Every system is different, Some of my tanks I do biweekly and some monthly, I have one that is going on 10 months no water changes but thats another story.


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## Roccus (Nov 1, 2013)

another thing about water changes... if you allow the Nitrates and phosphates to accumulate.. you are going to battle algae ... more so than if you do small water changes weekly of bi-monthly...


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## argofan (Jul 29, 2015)

thanks, Its happening now. my tap water has between 5-7 ppm phosphates
gotta figure something else out

many thanks

kevin


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