Nitrogen Cycle - jumps in pH

Hi! So I’ve been cycling a 5.5 gallon planted tank now for a week. Hoping to add one female betta. On the 8th I had the following readings:

pH: 6.6
Ammonia: .5ppm
Nitrites: .5ppm
Nitrates: 40ppm

Today my readings were as follows:

pH:7.0
Ammonia: .25ppm
Nitrites: 0ppm
Nitrates: 20ppm

I’ve been doing a 25% water change every day this past week while also adding just a few drops of API CO2 booster. When I first planted the tank I added API leaf zone. For a conditioner ive been using API stresscoat+ though will probably switch over to prime. I also have fluval stratum as a substrate.

I’m posting because I’m a little worried about the jump in pH in only a span of 3 days. Is that normal as the tank cycles?

also does anyone have any tips on reading ammonia? I have the hardest time distinguishing between the colors. Thank you!

 

If I am understanding correctly you are saying you are cycling this tank for a female Betta. I am assuming from this that there are no fish in the tank right now. If that is the case then all these water changes aren't necessary. How are you feeding the cycle? fish food? bottled ammonia?

If you ran your pH test at a different time of day that may explain the difference in the pH. Try to run it at the same time of day each time.

As to the colors. A lot of times it is best guess and we can usually guess it fairly close.

I am curious as to how you are moving this cycle along so quickly. Did you used seeded media from a cycled tank? That second set of readings is telling me this tank is cycled but if you didn't add seeded media the numbers may not be telling the whole truth.

 

Daily water changes will give "false" pH reading because fresh tapwater contains lots of CO2 and as the CO2 off-gasses the pH will rise.

That could explain your different readings.

 

There are no fish in the tank. I sprinkle in betta crumbles when I wake up and when I go to bed. Also I am using filter media from an established tank. But I had no idea that the time of day would impact readings. That’s so interesting!

Should I stop with the daily water changes and see how it goes from there? Also, could the CO2 booster be impacting pH?

Thank you!

 

There are no fish in the tank. I sprinkle in betta crumbles when I wake up and when I go to bed. Also I am using filter media from an established tank. But I had no idea that the time of day would impact readings. That’s so interesting!

Should I stop with the daily water changes and see how it goes from there? Also, could the CO2 booster be impacting pH?

Thank you!

Since there are no fish there is no need for doing water changes so often. Each time you do one you are removing the food (ammonia) bacteria needs to grow. The filter media is why your cycle progressed so quickly. By doing so you added the bacteria we are trying to grow when doing a cycle from scratch.

If it were me I would do a big water change with a deep gravel vac to remove as much of the fish food you have added as you can and then go ahead and put my fish in there. She will continue feeding the cycle.

I've never used a CO2 booster so really can't answer that question. I wouldn't think it would affect it though. If you run your pH test first thing in the morning and then again late evening I suspect you will get a higher reading with the late evening test.

 

Thank you so much for your help! I just did a bigger water change with the vac, conditioned with prime. Tomorrow or Sunday I’ll add a betta.

 

Thank you so much for your help! I just did a bigger water change with the vac, conditioned with prime. Tomorrow or Sunday I’ll add a betta.

Just keep a close eye on the perimeters. If you should see any ammonia do a water change and if possible add a bit more seeded media from your established tank. As long as the ammonia stays .5 or below you can wait a day or two to do a water change as long as you have added Prime.

 

I checked the water today, everything very similar to the reading on the 11th. 7.0 pH, .25ppm ammonia, 0 nitrites, and the only difference is that nitrates now read at 10ppm. I dosed with prime.

Thank you for all of your help!