Declining PH during a tank cycle

[saltwatercube]

Hi all, I am day 13 of a fishless cycle. It's all looking good and I used a seeder stick of bacteria from a LFS that came highly recommended by my local facebook groups and reef organizations. The only issue is, since adding, my PH has dropped daily and now it is somewhere around 7.4-7.6 when it was at 8.4 originally. I have looked at so many conflicting research and opinions on how low is too low and if water changing it detrimental or a saving grace when the PH is low. I am using API to test, yes I know they are not the best but for cycling it gives a good idea and I plan to invest i better kits for ALK, phos, calcium, etc. I am attaching the data from my spreadsheet to take a look at. What should I do? Leave it? Water change? Use a buffer? I have seen so much conflict over when to/not to intervene on PH that I am stuck. It does not seem to be negatively affecting my cycle at all, but I figured I would put it out there and ask.

TIA

 

[Troylee]

It’s not gonna hurt anything without corals in your tank.. what’s your salinity and alk look like? Do you have a skimmer or anything on the tank? It sounds like the tank has taken on excessive co2 which is fairly easy to cure by opening a door or window etc.

 

[crabgrass]

dump the water out, get new rocks and sand and start over, cycle failed.

jk, don't worry about it at this point. Expect lots of fluctuations in all parameters over the next 2-6 months (outside of Ammonia and Nitrite - those will be zero'd out in another week, if not already)

 

[saltwatercube]

It’s not gonna hurt anything without corals in your tank.. what’s your salinity and alk look like? Do you have a skimmer or anything on the tank? It sounds like the tank has taken on excessive co2 which is fairly easy to cure by opening a door or window etc.

My salinity is 1.025, I monitor that every day. I don't have anything to test alk, phos, or calcium yet, but plan on getting soon. I don't have a skimmer yet, but plan on getting one this week. The tank is in the (finished) basement, so that is very probable. Would a fan help in the mean time?

I was mostly worried after seeing lots of people say it could stall a cycle, but if it won't hurt anything I'll work on finding a solution, just worried it was a more urgent issue.

 

[saltwatercube]

dump the water out, get new rocks and sand and start over, cycle failed.

jk, don't worry about it at this point. Expect lots of fluctuations in all parameters over the next 2-6 months (outside of Ammonia and Nitrite - those will be zero'd out in another week, if not already)

Haha! Thanks so much! I was just worried it could stall the cycle but I appreciate the reassurance.

 

[crabgrass]

Haha! Thanks so much! I was just worried it could stall the cycle but I appreciate the reassurance.

you should be good to go to add a fish or two in a week. Your Ammonia and Nitrite is problably 0 tbh - those tests are questionable.

As others said, you'll want to wait until the rest of the parameters (N, P, Alk, maybe PH) stablize a bit. But

 

[Randy Holmes-Farley]

Cycling lowers pH and alk as ammonia is converted to nitrate, but I don't think the pH 7.4 is likely accurate anyway.

 

[saltwatercube]

Update, in the weirdest and simplest fix ever, I adjusted my modular skimmer overflow grate so it was higher up and the water trickled into the AIO compartment instead of just flowing in and that changed everything, the PH went up to 8.4. Going to get a protein skimmer and more aeration in the room to help in the future. Thanks so much for the help everyone!