pH questions

[Mouse51180]

I have a pH issue with my tank. It stays at roughly a 7.6-7.8 level. I only have fish right now, but would like to get into corals. I have added the powder buffers to get my tank to the 8.2 range, but after a week the buff is all used up and the pH drops back down to the high 7.x range again.

I asked in the chat room if pH was supose to sustain itself which Len told me it was. She\He advise me to stop putting the buffer in since it was only a temp solution. She\He said to crack and window in the house and get some fresh air, or if it was a closed tank to open it up a little or have the skimmer suck air from outside the under-tank cabinet it is in.

If I added an air pump, pumping into the sump or an air stone in the sump...would this help in getting my pH up?

Is there any other way to get my pH to get up to the 8.x range and get it to stay that way without adding powder or liquid buffer every other day?

I would like to have a drip system, but am limited on space right now, so that is not an option.

Thanks for any other advise you can give...im still a novice in this whole thing.
Mouse

 

[Anonymous]

In addition to what Len said you really should check your Alkalinity and Calcium levels. If you've added too much buffer your Calcium will be bottomed out and your ALK will be too high. If so then you really need a few good sized water changes to get these levels balanced again.

Increase water circulation if it's less than about a 20X turnover rate.

Make sure there's no accumulated detritus or clogged mechanical filters.

The airstone in the sump will help PH but it can make more of a mess than it's worth.

 

[Anonymous]

The reason for cracking a window (I assume) is to help drive off some of the carbon dioxide in your tank. Fish give off carbon dioxide just like we do, the CO2 dissolves in water to form carbonic acid. This combined with the added contribution of nitric acid as a result of the nitrogen cycle, and the net concentration of acids in an aquarium will increase over time.

Alkalinity is essentially the concentration of bases in the water. ...I've found that the best way to think of it is as a sponge. The higher the alkalinity, the more acid the sponge can absorb. By 'absorbing' or neutralizing the acids, alkalinity thereby 'buffers' the pH higher. Alkalinity is 'consumed' in the process. In a system, the alkalinty will drop slowly over time, and the pH stays stable. But once the alkalinty reaches a certain point, the pH will plumet like a rock. If you've got lots of carbonate in the tank (substrate, corals, etc) it probably won't fall much below 7.4-7.5.

I agree with Guy, you need to test your alkalinity, and get it back up to a 'normal' level for the aquarium. Normal seawater has an alkalinity of approximately 2.3-2.6 meq/l (~125mg/l or ~7dKH); it is generally advisable to maintain an alkalinty slightly higher (to help maintain pH stability)...I'm sure someone else could chime in on the appropriote alkalinity, but I'd try and put it closer to maybe 3.5 meq/l (180 mg/l ~10 dKH).

I'd also agree that maybe a water change is in order, this will help correct the ratio of acids to bases...the ratio that determines your buffer capacity.