Is this ok?

[pezcaito]

I have a 30 gallon freshwater community tank and I have it set up like this:
I have a fountain type filter with a cartridge that I have added extra carbon.
One powerhead filter with a tube that goes into the gravel (sucks up a lot of the gravel debris) and the fish love swimming in the bubbles.
a Pothos plant
A moss ball
pond gravel
I have 4 mystery snails
2 assassin snails
3 ghost shrimp
2 dwarf plecos
2 small cory fish
4 mollies
3 Platys
6 neon tetras
3 zebra Danios
2 Endler guppies
8 common guppy fry
5 platy fry
a bunch of pond snails...

The issue or non issue is that the water is clear, the glass is clear, the fish are healthy and swimming fine, I have not done a PWC in over a week, I have also not rinsed out the filter cartridge in over a week as well, there is a slight odor (not much though) and I checked the cartridge and its almost completely clean. I added some bio cleaner and I added water I always add water conditioner. Is this ok? do I need to do a PWC anyway? or should I wait until it really stinks or the cartridge is gross? The tank seems super healthy other than the faint smell...

 

[Ktownmatt]

I wouldn't rely on smell or appearance.
Buy an API Master Test Kit, and test the water for Nitrates. Assuming your aquarium has been cycled, the main reason for a water change is to keep the Nitrates under 40ppm.

 

[charliebankston]

I wouldn't rely on smell or appearance.
Buy an API Master Test Kit, and test the water for Nitrates. Assuming your aquarium has been cycled, the main reason for a water change is to keep the Nitrates under 40ppm.

I agree. If your nitrates get too high (only a 25-35% water change will lower them. Adding back water lost from evaporation doesn't count) then your fish could die. Most likely they will slowly acclimate to rising nitrate levels, then when too high they'll just slowly start dying off. The more sensitive ones like shrimp etc first. Also, you'll have "old tank syndrome" so if you add new live stock in, they'll die after a day or 2. Or when you do a water change finally, the sudden dip in nitrates and higher ph from new water will kill everyone.

 

[pezcaito]

would a 10% water change be enough? I usually go for a 50% water change once a month. How much is enough on a weekly basis?

Thanks!

 

[charliebankston]

Depending on your stock level and how fast the nitrates build up dictates your water changes. I do 33% monthly on some lighter stocked tanks we have, 25% weekly on heavily stocked. That's on bigger tanks too. 10% is generally not enough if that's the only water change, period. But 10% weekly and 50% monthly could work fine as long as your water parameters stay good

 

[charliebankston]

A buildup of fish waste and uneaten food will slowly lower the ph too, then when a large amount of new water is added the ph jumps up and that's hard on fish as well. Steady clean water parameters is the key