PH is dropping and difficult to hold--Need Help

[flameangel88]

I added a couple of Genicanthus angels on Thursday morning and Friday morning one of them was missing and that night a female bellus angel had a pop eye was also partly cloudy. The bellus is holding in the back of the tank between 2 large pieces of base rock I can see it swimming but not enough to get a picture at that angle. I can see the cloudy eye has a couple of short white thread like material hanging out around the edge of the eye. I dosed Prazipro Friday night and shut off filter with carbon and took the skimmer off-line as well and since dosing Prazipro the PH has been dropping to 8.0 and barely able to hold at that level. I added Marine Buffer 8.3 the last 2 nights just to hold it there and I'm about to dose for the 3rd time otherwise PH will drop again.

The tank is 180g with plenty of flow. With about 260 lbs of LR and 100 lbs of LS. This was an updgrade from a 75g back on last October and the 75g was running for 16 months prior to the current upgrade.

I tested the parameters last night and tonight and there were the same:
PH 8.0 (after dosing last night it betw 8.1-8.2)
Ammonia 0
Nitrite 0
Nitrate 80 (this was around 40 couple of weeks ago)

1)What may be causing the PH to drop continously?

2)The infected bellus angel's eye has cleared a bit and less of the white thread like stuff around the eye. Przzipro seems to be working but it's also having aneffect on the other fishes as they swim a little different especially not swimming as fast as they used to. Should I start running carbon and skimmer now or I should hold out for one more day to let the Prazipro to work?

I don't know if this info is of any relevence but just in case--I've 3 lg Cleaner Shrimps and 3 lg Fire Shrimps and all 6 seems to be fine and one of the Fire Shrimp just molted

I greatly appreciate any suggestions for the next course of action I should undertake here!

[Percula9]

Never medicate the display tank. You should have removed the fish to a quarantine tank and treated her there. You probably will have treat for secondary bacterial infection any way. I suggest you start setting up a QT tank. The pH has not dropped to a unsafe level. Like I said, remove infected fish to a QT tank. Perform a partial water change on your display, and turn your skimmer back on and add carbon to remove the medicant.

[bertoni]

1) The PraziPro might have killed off small animals, I suppose, with the resulting decay lowering the pH, but that's hard to say. 8.0 isn't low enough to cause any problems, especially for a fish-only system.

2) I am not sure that I'd count on the disease being cured yet.

[marcrothschild]

My tank is 7.7-7.9 with no problems. If your adding buffer, check your alkalinity. Dont sweat the pH too much

[Billybeau1]

And please, stop using that marine buffer to maintain pH.

Your alkalinity is probably through the roof by using that product.

There is nothing wrong with a pH of 8.0

Do not get hung up trying to keep your pH at 8.3

The recommended range is 7.8 to 8.5

[flameangel88]

Thanks for all the quick replies. I've started the skimmer and normally it would have gone nuts but this time it was only the 1st 1/2 an hour and its skimming more normal now. I'll run carbon tomorrow after a partial water change as I still want to give it another day for Prazipro to work.

Thanks again for the great info on the PH level concern. I'll keep an close eye on her and treat for baterial infection if needed.

[Billybeau1]

Keep us posted. :)

[flameangel88]

Thanks again to everyone for advising me not to be overly concerned with the PH level esp on NO more dosing of Marine Reef buffer to maintain PH.

To recap: the Swallowtail went misssing on Friday finally turn up on Monday morning stuck on the side of the powerhead and the body was still in very good shape with no marks but the head to gill area was badly decomposed. I don't know if the tank ever experienced a cycle in such a short time or not and the test during the 3 consecutive days were 0 for ammonia and nitrite.

I was still uncomfortable in stopping the Prazipro by running carbon and WC so I had the skimmer turn on Sunday and waited till last night (so Prazipro was in for 5 full days) to run the carbon and WC(20%). As of last night the female Bellus's eye took a quick turn toward much more clearer compared to the night before. I'm not sure if she is out of the woods yet but I'll have Maracyn II in tomorrow if she doesn't get better and need to treat for bacterial infection.

Here's short video of her and I welcome any comments or recommendations for course of action. Thanks again for the help everyone provided here!

http://s75.photobucket.com/albums/i287/reeftankpix/Genicanthus/?action=view&current=MVI_0374.flv

[NormanB]

Don't sweat the pH use Reef Builder for alk keep it at >or= to 4.0 meq/l and the pH will stay in line.

[Randy Holmes-Farley]

Reef Builder and other buffers are not a good way to control pH, despite manufacturer claims.

[flameangel88]

<a href=showthread.php?s=&postid=12040625#post12040625 target=_blank>Originally posted</a> by Randy Holmes-Farley
Reef Builder and other buffers are not a good way to control pH, despite manufacturer claims.

Thanks. It's on my list of things to remember.

[Randy Holmes-Farley]

I meant the comment more for Norman, but that's good to hear. :)

[NormanB]

<a href=showthread.php?s=&postid=12043374#post12043374 target=_blank>Originally posted</a> by Randy Holmes-Farley
I meant the comment more for Norman, but that's good to hear. :)

Randy, would you mind going into more detail? From my experience with Reef Builder is if I keep my alk at 4.0 meq/l the pH stays 8.1-8.2.

Please help me understand.

[bertoni]

The pH of a tank is set by the alkalinity and the carbon dioxide content of the water, assuming the decay rate is low. Alkalinity supplements can raise the pH both by adding alkalinity and by consuming carbon dioxide from the water. Aeration acts to move the gas content of the water column to equilibrium with the air, and undoes the carbon dioxide consumption.

Reef Builder will raise the pH a bit when added, I think, but it's the carbon dioxide level that tends to be the issue. Your tank is in a relatively friendly atmosphere.

[Randy Holmes-Farley]

pH solutions that work for one tank will not necessarily work on others due to the effects of atmospheric CO2, as Jonathan points out. If you have normal air in your home and normal alkalinity in the tank, then perfect aeration will not allow the ph to ever be below 8.1.

But many homes have elevated carbon dioxide, and that drives down pH even with adequate aeration, alkalinity and buffering of the water.

I show that in this article:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

[NormanB]

Thanks guys!

[Randy Holmes-Farley]

:thumbsup:

Happy reefing. :)