Lower pH (effects of aeration and black algae)

[Marble128]

I need to lower my pH in my fresh water 20 gallon tank. My pH is around 8.4, though usually hangs out around 7.4. I have some black algae in the tank so I bought Excel to take care of it. I am doing 25% water changes weekly. I have fish, gravel and plants in the tank. All other chemistry readings are normal.

Guy at my aquarium store said to decrease aeration in tank, cause that would increase pH. Though everything I see online says to increase aeration.

I am thinking the spike is due to the algae. Thoughts?

 

[Watsonja4]

An increase in oxygen aeration will increase PH, an increase in carbon dioxide injection will lower PH. You can also try driftwood and I think peat moss if you are looking for natural ways to lower PH.

 

[enrgizerbunny]

I'd like to know why your tank pH is so low compared to your tap. Black algae? Have you checked your gH and kH?

Increased aeration will increase pH if you have an abundance of CO2. Remember, stable pH is far more important than "ideal" pH.

Sent from my SCH-I435 using Aquarium Advice mobile app

 

[aqua_chem]

My pH is around 8.4, though usually hangs out around 7.4.

Can you explain what you mean by this? It's 8.4 out of the tap, but 7.4 in the tank? Or it ranges between those two measurements in the tank?

Can you tell us more about your setup? Particularly the lighting, plants, fertilizer, and age of the tank? I would also love to see some pictures of this algae, as 'black algae' can mean different things to different people. Adding an aerator probably isn't going to do much for BBA, but it might for BGA, which might be what your guy is thinking.