Ferts Raising Ph?

[nikkifro8994]

I'm trying to figure out what's going in with my ph. The water I add to the tank has a ph of 6. The water I pull out of the tank (2-3 hours after I do a water change) has a ph of 8. I use flourish root tabs for fertilizer. This is the only thing I can think of that would change the ph. Ammonia and nitrite are 0 and nitrate is ~10. What's going on with my ph?

 

[PrairieSunflower]

I don't know but that puzzles me. I have been having the backwards problem.... I've always had water at 7.4... as in as long as I've had fish. Then recently it dropped to 6.8. Tested my water and that is what my tap water is as well. I've blamed it on the tap water. But after reading yours.... I'm wondering.... could my tank have always been 7.4... I only recently started adding ferts to try and reduce algae growth... then found another way and stopped... and... that just might coincide with my pH drop....

 

[nikkifro8994]

I have another tank that has a ph of 6, but the water I add to that is 7.4. It has neon tetras, so they don't mind. My other 3 tanks have the same ph as the water I put in. I don't get why I have one that goes up, one that goes down, and 3 that stay the same. It's very puzzling.

 

[techen]

Hey there, What substrate are you using? A lot of these plant ones will rise or lower your PH, Also bogwood can play with PH as well.
 
It does take tap water awhile to let off the trapped gas and adjust to the real PH value so this might be something to check as well.

 

[deftuch]

your water may have a really low permanent hardness. and plus what other compounds are in your tank may be effecting the hardness and also the ph? sounds like you need to do some technical research lol