You probably have a considerable amount of co2 coming from the tap. Do this, test the ph out of straight out of the tap then leave a cup of water out for 24 hours and retest. My tap well water comes out at a ph of 6 but degased it climbs to 6.8.So, I am cycling a new 120 and researching fish. This will be a well stocked tank in terms of both fish and plants. I read often that the fish I'm looking at are sensitive to pH swings and other parameter disturbances. I have a Python to do changes. We use tap water: its pristine well water with a softener system. Nitrates are zero in my tap water: GH is 6; KH is 10.
My pH has me baffled. I have had a low_tech Wyman dirt 36 planted tank for 3 years, and pH starts at 7 from the tap and goes up into mid 8's w/o weekly changes. I figured it was the dirt, so in the new 120, I've decided to go high tech, hi lights and pressured CO2, with ferts, and I chose an inert substrate this time: Black Diamond blasting sand.
1) Been cycling about a week (no CO2 or ferts yet, andabout 1/5 planted) and testing daily, and pH is again climbs to low 8's between water changes. I even have driftwood in the tank! ??? Anyone have any ideas why my pH spikes?
2) And, also, how am I supposed to do the suggested EI water changes (weekly 50%) without major pH swings that may kill fish?
Ah ha! Thanks for that reply. It gives me the first clue for what's been going on. I am looking at getting Denison Barbs, rainbowfish, and an angelfish or two. Also a gourami. And then I will have snails, and some Cory cats. As I've been researching I've been only looking at fish that will work with my somewhat basic and somewhat hard water out of the tap. These seemed like good candidates, but I kept reading about the dangers of pH swings.You probably have a considerable amount of co2 coming from the tap. Do this, test the ph out of straight out of the tap then leave a cup of water out for 24 hours and retest. My tap well water comes out at a ph of 6 but degased it climbs to 6.8.
5t
Your ph will swing regardless due to running co2 as it causes the ph to drop.
What fish are you looking into?
Thanks! I am clear on that, hence my fish list. The only fish that I know of on my list that even approaches that category is the angelfish. I am planning on getting said angelfish from an outfit in TN that raises theirs in pH is of 8.0 and above. And I'm planning on my Cory cats to be ones that tend toward that higher range as well (Sterba).Your water isn't very good for keeping more sensitive, low gH, pH fish. Keep that in mind.
