Sudden High Ph In Cycles Tank

I have a fully cycled tank. It's been running for over 6 months. It is fully planted. A few weeks ago I had a major algae outbreak and cyanobacteria outbreak mainly due to phosphates and poor water flow. I noticed random air bubbles in the water. At all points had 0 nitrates, nitrites, and ammonia.

Anyway, a bunch of fish died so I started doing all the tests. The only odd reading was my Ph was over 8.8. My tap water runs around 7.6. Something is creating a high Ph. Peat Moss didn't help so I started using an acid buffer and that has lowered it to 8.2, but this isn't a long term solution. I've been doing 30% water changes 3 times per week. One of my AC filters was old and broke (I've since remove it but I thought it might be relevant).

Any ideas what might be causing the Ph to spike?

 

Also, if your thinking "it would make sense if the water was going acidic and not alkaline." You wouldn't be alone. I've already consulted local shop owners and gurus to no avail

 

algal blooms can raise ph. so can increased water hardness if you often top the tank off you will over time increase the hardness of your water and at a certain point will begin influencing pH

 

Can you upload a photo of the tank and describe what substrate and decor is used?

 

My tap water is notoriously unstable for pH

I tried all the gizmo's and additives to no avail.....so bought bottled water with a specific pH and have not looked back. My three aquariums have nothing but bottled water & MopanI wood and the fish are happy & healthy and no spikes in anything

Bottled water always has on the label what the pH is, I buy around 100 litres a fortnight and that handles all water changes etc without any issues. It saves stressing over the tap water quality.

 

I can upload a photo once I'm home, but nothing has changed as far as substrate/ decor for the last 4 months.

 

Have you tested it out to see if the PH of your tap water goes up over time? It is possible that your water company has changed the way they treat the water at its source and that is why the PH in the tank is now going up.

To check this out put some tap water in a container. Add whatever water conditioner you are using in your tank and anything else you may be adding. Run the PH test for a baseline. Put an airstone in that container. Let it run for 24 hours and then run the PH test on it.

If the PH of this water goes up you will have your answer as to why it is going up in the tank. If it doesn't go up you will have to look elsewhere.

 

it would help if you can get your tap water and tank water tested for GH and KH. the API GH/KH test kit goes for around $9 shipped on ebay.

 

Well water for the win