Cycling 125 G Ammonia now at 0/ Nitrites Really close to 0 / Nitrates Really High

[gjustinj]

Hey guys,

So it's been a few weeks I've let the tank cycle (thanks for all the input), today I did my tests and sure as you guys said The Ammonia and Nitrites really happened nearly over night.

What are my next steps? I assume a water change is necessary right away? How big of a % should be completed? Then can I take a sample of water with me to the fish store and get a fish yet? or is there another step?

Thanks all!

HAPPY EASTER!

[mcgyvr]

yes you will want to perform water changes as needed to get nitrates down..
once those are at an acceptable level then you can start adding creatures..

[nereefpat]

Originally Posted by gjustinj

I assume a water change is necessary right away? How big of a % should be completed?

Theoretically, you can do a 100% change. Almost all the bacteria are on the rocks and sand.

This isn't​always very practical, so a couple large water changes would work also. A 50 gallon change, followed by another 50 gallon change the next day would drop nitrates about 75%, for example. Then start with your weekly 10% changes.

If you plan on only adding fish and cleanup crew, nitrates below 30ppm or so is plenty safe.

[gjustinj]

Thanks guys! I'll do a 50% and another 50% and see where those nitrates are!