I am probably talking too much on this forum, but I could not resist your post as it sounds sooooo familiar (I have a 55 fresh, had it for a long time and then bought 125 Marine set-up and lost many a fish to PH
bounce at the begining of my trials and tribulations).
I use the same Buffer Kent Super dKH
buffer in my FO
tank. It is an excellent product and helped be out greatly when first getting my water chemistry set. As you likely know PH
is a measurement of ionic balance between Hydorgen and Hydroxl, typically referred to as Acid vs. Alkilinity. There are two other chemical properties which largely dictate how PH
will behave in a solution. Together they are usually referred to as buffering. Buffering comes in 2 flavors - Calcium/magnesium compounds (general hardness) and Carbonate hardness (repectively gKH and dKH
). The buffering does not really effect the PH
directly but sort of stabilizes it by providing molecules that will bind with the Ions that affect PH
. For example as an acid is added to a solution (let's say your tank water, let's say via the cycle, i.e. Nitrates - which I believe is Ester of Nitric Acid), if there is a high level of hardness then the PH
will not shift to the Acid side - i.e. NO PH
BOUNCE. If there is no buffering then the additional acid will imediately shift the PH
You can use Super Buffer pretty freely until you reach your desired PH
but only add it at the doses recommened by the package. Also monitor PH
closely as it can cause PH
drift - i.e. it will continue to neutralize all Hydroxl Ions in the tank until the PH
starts to rise above say 8.3 - this happened to me and for a while my tank was running at 8.65 and It took me many a 40 gallon tub of RO
water to remove enough buffering to stabalize the PH
in the 8.3 range.
I'd be a little surprised if 7.8 killed a fish that quickly - for one thing, since PH
is based on Log, 7.0 being 10 times as acidic as 8.0, 7.8 is not that far off from a comfortable 8.0 for that fish - it seems he should've been able to handle that for a while and you would have noticed some stress behaviour for perhaps a week before his demise - but that's only a guess. What test kits are you using, perhaps your PH
is actually lower. You might want to consider a 100 buck investment in a pinpoint monitor.
I've found that with Buffering PH
- go slow and measure alot (as suggested earlier, once in the morning and once in the evening as Lighting and daily organism activity affect PH
). Once you hit the target PH
with the super buffer (and this can sometimes take awhile) it will actually be very difficult to lower your PH
even if you wanted to.
Anyway hope some of this helps.