Tank is Cycled Now What

[MapleNeil]

My tank is cycled now, and nitrates are staying below 10 on their own. I guess the plants are eating the nitrates.

How do I know when I need to do a water change? If ammonia, nitrite and nitrate are all acceptable, then can I just top up once a week after I vacuum the substrate? Or should I measure something to know when I need to change water.

 

[charliebankston]

You should do a water change according to the bio load. For example, i have some big fish/ or heavily stocked tanks i do a weekly 25%. My bigger lighter stocked i do a monthly 33%. Start with just a few fish at a time to not overload the bio. Don't add too many at once, giving it time to grow bb to consume ammonia. Your right, your plants will consume nitrates. I put a tiny mark on the edge of my tanks with a sharpie so I know when I've removed the required amount of water. Don't do less than 25% no matter the frequency, and don't go longer than 4 weeks

 

[charliebankston]

Sounds like you've done a great job so far!

 

[MapleNeil]

Thanks for the help!

It wasn't such a great job, because it was a fish-in cycle that I started before I knew enough to do things properly.

But since the ammonia and nitrites went away, I added more fish, and now even the bio-load from the fish isn't enough for the plants, and nitrates are going down and I have to add fertilizer.

Is there something I can measure to let me know when a water change is needed? Other than just doing a minimum amount on a regular basis?

 

[charliebankston]

Not that I'm aware of. Water testing, which your already doing. Keeping parameters and ph steady, along with removing detritus is the main reasons for doing water changes

 

[Aiken Drum]

This is a good guide from aquarium co op on determining how often and how much to do water changes.

 

[Aiken Drum]

Link to actual page. Might be easier to read.

https://www.aquariumcoop.com/pages/water-changes