pH dropping

[howmanyds]

For several months while cycling, my pH stayed consistently at 8.2, where my tap is. For some reason, even though nothing has changed except that the tank has finally cycled, the ph has been dropping recently. It's now about 7.9 about four days after my last pwc. What could be causing this? The thin layer of brownish algae that is on my shells and rocks? I want to get this figured out before my fish arrive tomorrow!

Thanks.

 

[howmanyds]

You can see some of the brown algae here.

 

[wildroseofky]

That brown stuff is diatoms. It appears in almost all new aquariums. It will go away after a while. It took mine about 2 months. Just wipe it off of the decor and plants until it does. What type of fish are you getting? The PH seems high to me. Mine stays arounf 7.2 to 7.6 and I have mollies, neon tetras, shrimp, and snails. I know some fish require higher PH. Mine started dropping after cycling and I added some limestone, eggshells, seashells, and the occasional pinch of baking soda when it dropped too low. I was told to get crushed coral or cuttlefish bone to buffer the PH and keep it from dropping but I couldn't find it in my area. The limestone and eggshells have really helped it. Even with CO2 my PH has been staying stable for the last few months. You just need to add enough stuff to keep it buffered. Hope some of this helps.

 

[howmanyds]

I'm getting African cichlids, so I plan to keep it at 8.2 or so. How
Much baking soda should go in when the pH drops 2/10s?

 

[wildroseofky]

It only takes a little to raise the PH. Start with 1/4 tsp. Let it mix with the water for a few minutes and check PH. Just add a little bit at a time checking in between adding each dose. When you have it back to were you want it, figure out how many 1/4 tsp it took and that will be what you need to add when it drops again. I found that it would last a few days before it started dropping again. You will also need to buffer the water so it will not keep doing it. If you can find crushed coral you can use that. Or cuttlefish bone. Maybe some other cichlid enthusiast will be more helpful with what they use.

 

[howmanyds]

What does it mean that it took 4.5 tsp to raise it from about 8.0 to 8.2? Is my buffering capacity pretty high already?

 

[wildroseofky]

I am not sure what it means that it took so much to raise the PH. Do you have a KH test kit? If your KH is at least 7 than you are buffered enough if I am getting it right. That is for CO2 though. Have you tried doing a search for PH and Cichlids? I know a lot of the members on her keep them.