Ammonia not changing

Jack_soho · 2026-09-17T19:53:16-0400

Hey guys, i recently put my nitrifying bacteria (Dr. Tims) about a week ago to start the cycle. Not sure if i put it in too early, I added 16mL of ammonia to my tank (90 gallons including sump) and i tested ot yesterday and today. it has been measuring 0.5 ppm. What do i do? Leave it or restart the cycle?

Also brand new to reefing so any tips help Thanks!

Fish Fan · 2026-09-17T21:04:45-0400

Welcome to Reef2Reef

#WelcometoR2R

Nothing to worry about at all, this is common with Dr. Tim's bacteria. It can take a couple two or three weeks to see the ammonia going down, despite what it says on the bottle.

Honestly, I'd add a little more ammonia, you usually want the concentration about 2.00 ppm or so to start your cycle. Once that level drops to about 0.50 ppm or less, you're in good shape to add some hardy livestock

Good luck!

Jack_soho · 2026-09-17T21:09:08-0400

thanks man! i may have added the ammonia to late, i added it about 3 days ago? how much more should i redose?

Fish Fan · 2026-09-17T21:24:44-0400

Jack_soho said:
thanks man! i may have added the ammonia to late, i added it about 3 days ago? how much more should i redose?

So you added the bacteria and then a few days later added the ammonia? I don't think that's a problem at all.

I usually suggest bringing the ammonia up to about 2.00 ppm, I would test it with a test kit and let that determine how much to add.

EnterName · 2026-09-17T21:31:08-0400

Jack_soho said:
thanks man! i may have added the ammonia to late, i added it about 3 days ago? how much more should i redose?

If you have an ammonia test kit just test and dose the appropriate difference to 2ppm. Otherwise just add 0.5ppm or so and it will be fine.
You won't need to add more bottled bacteria imo. A healthy reef tank has like 90 different bacteria families (https://aquabiomics.com/articles/core-aquarium-microbiome), Dr. Tims has 10 - 30 or so (https://humble.fish/community/threads/bottled-bacteria-results-tims-one-and-only.20952/), many of them probably chosen to survive being bottled and not chosen to actually represent what will be in a reef tank long-term. The bacteria will establish without adding any products. The only thing I can recommend is adding some phosphate if you don't have detectable phosphate levels already, and maybe a few mL vodka or vinegar (e.g. 1mL per 100L, once). This will give all bacteria a kick start made from carbon, nitrogen, and phosphate.