Prometheus

I have a 30 gallon tank

So, I went to the store and had my water tested. Apparently everything seemed okay except they told me my pH was way too high at 8.4. They say the tap water around here is at 10 but the pH will naturally drop down after a while in the tank. I have platys, a gourami, lampeye kilifish, oto cats, and neon tetras. They are telling me the pH is too high for these fish and I should add neutral regulater to bring it down. I already happen to have the stuff but I don't want to add anything if I don't have to. The guy was also shocked that I haven't done any major water changes except for just topping it off. He also says that something is driving up the pH and I have to take it out or it's just going to keep getting higher. It's been two months maybe, since I set up the tank with soil. The plants are great but now I'm concerned about the fish. When I set up the tank I added oyster grit to the soil because the city water here lacks hard water nutrients. I assume that's driving up the pH. I can't exactly take the oyster grit out of the soil

I dont know what to do or if I should do anything at all. Is this an issue with these fish? Do I need to introduce something that will keep the pH lower? Is there something other than chemicals that I can do.. like add peat or maybe somekind of bogwood?


My second question is about the filter. I have this aquaclear HOB filter which is creating too much water agitation and a lot of noise and I dont feel like topping it off every few days just to keep the noise down. I want to get rid of the filter. Can I do that with a 30 gallon? How do you know when it's safe to take it out? I also have some fuzzy light green algae on the glass and on the driftwood in the tank but it comes off easily. I do have water sprite I just introduced two weeks ago so I am not that concerned about more algae but if I take out the filter there will be no water circulation. Does anyone have any thoughts about this?