pH drop during cycle?

[jjarbo1]

I'm cycling a saltwater tank with live rock and a rotting shrimp. The ammonia spiked, followed by Nitrites. Now ammonia is at zero, and Nitrites are still up... waiting for them to come down.

I noticed though that my pH dropped from 8.2 to 7.8... Is this normal?

 

[fijiwigi]

7.8 is ok however on the low side. When are you testing your PH your PH changes from morning to night. And a good way to raise PH is just a simple PWC but you don't want to do this because your tank is still cycling so a low PH will not harm anything since their is no life in the tank. Here is a good link to some info pH Control For Dummies - Saltwater Aquarium pH and Alkalinity Simplified

 

[Zagz]

Moved to SW getting started.

 

[Kurt_Nelson]

Yes... pH will swing all around during a cycle. Don't worry about it, and most likely after the water changes at the end of the cycle it will stabilize.

 

[Sadielynn]

One question is this an open top or closed ?
New systems generally have swings but it can be combated with an open top and opening a window . also new tanks usually tend to be lower on the PH but stablize out as they age .....
Couple things you can do .
Open the top .
Point a power head to the surface to get water movement .
Open a window for a bit ....
You want to get it up to 8.0-8.2 or even 8.4 ....Stability is key wich will start to happen as your tank matures

 

[roka64]

Also pH swings between lights on/off. Try to measure at the same time each day.

 

[pitt420dude]

Also pH swings between lights on/off. Try to measure at the same time each day.

It does? Why?

 

[Sadielynn]

It has to do with how the reef produces O2 and utilizes it here are a couple links that explain it a bit better
pH, the power of hydrogen

pH - The Power of Hydrogen

 

[Devilishturtles]

Photosynthesis consumes CO2 and releases O2 during the day. At night, O2 is consumed but CO2 is not, so it builds up. Accumulated CO2 in the water causes pH to drop at night, which is why it's usually lowest in the morning and highest at the end of the day.

A side note about test kits... high levels of ammonia and nitrite interfere with the chemicals used during testing, so testing anything but ammonia, nitrite, and nitrate during the cycle is pretty much not needed at all, unless you just want the practice.

 

[jjarbo1]

My nitrites and nitrates are pretty elevated so they might be affecting the test. It is also a closed top so I will keep that in mind. I did put two powerheads in and opened the air intakes to aerate the water to try to raise the pH, but it didn't do much.

I'll just be patient and wait for things to stabilize. Thanks all!

 

[Kurt_Nelson]

My nitrites and nitrates are pretty elevated so they might be affecting the test. It is also a closed top so I will keep that in mind. I did put two powerheads in and opened the air intakes to aerate the water to try to raise the pH, but it didn't do much.

I'll just be patient and wait for things to stabilize. Thanks all!

Using the bubbler feature in the powerheads won't really aerate a SW tank... just make a bunch of microbubbles!

All tanks that are cycling go whacko on the pH. It just all due to the massive amount of biological activity that's going on in there. Since there's nothing in your tank, consistancy in water parameters isn't an issue. Once you finish the cycle and do several water changes to get you nitrates back down, your pH will even out. THEN... if you have issues, start tracking down the source.

 

[roka64]

I agree with Kurt. That lid will also keep the pH low, since the O2 exchange occurs on the surface of the water in SW.

 

[Kurt_Nelson]

I guess my point is just ignore pH during your cycle.

Lid or no lid, excess CO2 in the house, not enough aeration, junk salt mix, overstocking, misreading colors on a pH test, day or night... shoot there are tons of things that can drive down pH. But trying to troubleshoot them during a cycle is pointless.