Can a high pH kill my flowerhorn?

[duanes]

Flowerhorns are a hybridization of 2 or 3 Central American cichlids (maybe more).
One of the most obvious is Amphilophus trimaculata, its natural waters pH usually averages around 7.5.
Another might be one of the Herichthys group, where its natural pH can run 7.5 to almost 9.
The genus Vieja is another likely suspect where pH can range again from 7.5 to almost 9.

One reason that a tanks water can rise in pH, is that under pressure in the pipes of a distribution system, gases like CO2 are trapped, and not released under pressure until that water is put in the tank, as water enters a tank, these gases are released, so pH naturally rises.
It could also be that the substrate has a calcium based sand, or that a rock containing limestone is in the tank, which will also raise pH.
I have a feeling it has more to do with trapped gases being released.

If when you draw a glass of water, micro bubbles form in the water and on the side of the glass (sometimes water appears cloudy), but then water clears from the bottom up (bubbles rise), this is an obvious sign of trapped gases.

 

[Magnus_Bane]

Love that Magnus_Bane ID! So your pH is that high & the FH's still do well? That's good to know. I'm still waiting for tank to cycle & don't have my FH's yet.
Since you have experience in FH, do you believe them to be hardy fish? I'm skeptical about a local pet store's offer to get me 2 FH's for $10 each (just seems iffy). I assume they would need to be quarantined if I had another FH already in tank.
I see much about this segregation, but how long would it need to be?
Thanx for everyone's help!

Feeder Fish quote: "When in doubt, ask your Flowerhorn!"

Yeah my FH's seem like they are happy to me atleast. And as for the $10 fish, well I got Jr. For $15 from Petco at .5in covered in ick and he grew up to be the fish you see in my profile pic. Also I would not recommend having more then one in a tank together unless you plan on breeding. When I bred mine I had roughly 3-400 fry and only got to sell 70 of them because they kept killing each other. They are mean lil fish and the smallest and weakest member of the tank is always on the menu. But yes quarantining is a must. But yeah FH's are tough fish and can take allot of punishment but I wouldn't recommend doing so to your fish as their over all color and growth is heavily affected by health and mood.