Phosphorous levels at start of N2 cycle

[chemistryman]

I'm cycling a brand new 10 gallon aquarium. I started it four days ago, seeded the aquarium with ammonium chloride solution until 4 ppm level was reached, then seeded it with Microbacter 7 to start the nitrifying bacteria population. The water turned cloudy yesterday, so there is a bacterial bloom (right on schedule).

I am doing the 30 day fish-less cycle method. There are no live plants, fish, moss balls, or snails in the tank. I test chemistry daily.


Before filling the tank, I washed all the substrate and silk plants with tap water, using a strainer and flushing until the water was very clear.

I used de-chlorinated tap water with a pH of7.0, TDS of 90 ppm and phosphorous of 1ppm max.

I checked the phosphorous in the tank yesterday and it was 10 PPM! Huh? Did it leech out of the substrate? Or the activated carbon bio-filter?

I plan to reduce phosphorous levels by planned water changes but only after I see the nitrate levels increase. Can I reduce them earlier? Why the increase in the phosphorous? Does it mess with the N2 cycle?


One more thing. I have been using small amounts of API Proper PH 7.0 to hold the tank pH at 7.0 during the cycle. Could this be the culprit? I put in 1/4 teaspoon in the filter every day.


Maybe I should let the pH swing and fix it at the end of the N2 cycle?

 

[Caliban07]

[emoji782]I'm cycling a brand new 10 gallon aquarium. I started it four days ago, seeded the aquarium with ammonium chloride solution until 4 ppm level was reached, then seeded it with Microbacter 7 to start the nitrifying bacteria population. The water turned cloudy yesterday, so there is a bacterial bloom (right on schedule).

I am doing the 30 day fish-less cycle method. There are no live plants, fish, moss balls, or snails in the tank. I test chemistry daily.


Before filling the tank, I washed all the substrate and silk plants with tap water, using a strainer and flushing until the water was very clear.

I used de-chlorinated tap water with a pH of7.0, TDS of 90 ppm and phosphorous of 1ppm max.

I checked the phosphorous in the tank yesterday and it was 10 PPM! Huh? Did it leech out of the substrate? Or the activated carbon bio-filter?

I plan to reduce phosphorous levels by planned water changes but only after[emoji782] I see the nitrate levels increase. Can I reduce them earlier? Why the increase in the phosphorous? Does it mess with the N2 cycle?


One more thing. I have been using small amounts of API Proper PH 7.0 to hold the tank pH at 7.0 during the cycle. Could this be the culprit? I put in 1/4 teaspoon in the filter every day.


Maybe I should let the pH swing and fix it at the end of the N2 cycle?

Probably phosphoric acid in the ph buffer. Also the phosphate test kit is said to be susceptible to interfering ions which could affect the accuracy.

 

[chemistryman]

True! I checked the bottle, doing small water changes now so as not to interfere with the nitrification. Thanks!

 

[Caliban07]

True! I checked the bottle, doing small water changes now so as not to interfere with the nitrification. Thanks!

No problem. You don’t need to use the buffer. pH isn’t a particularly important parameter.

 

[chemistryman]

Thanks. I agree. I did tests this morning. Nitrites are forming, so the 20% water change last night didn't kill the N2 cycle. PH is 7.0. NH3 dropped to 0.5 ppm.

However, I made a mess of things for myself because Po4 levels are still 10 ppm +.

Small, scheduled water changes should bring PO4 down, though. Unintentionally, I made a lot more work for myself (sigh).