I've said it before, I cannot do aquariums. Yesterday the ph was low so before I went to work I tossed in some baking soda. This morning I came home from work, turned the light on..I think just a tad too much. :ph43r: It looks like it snowed on the algae. I bought a plant/aquarium light to try to winter-over the water lettuce and a hyacinth. Good thing they haven't died out in the pond yet, cause they died in the puter room. :( ph is a wicked vivid pink...must be around 28. lol

Mathematically, pH can only range from 0 to 14. Sodium bicarbonate, baking soda, usually buffers no higher than a pH of 9.

If it makes you feel any better, I have never been able to overwinter water hyacinth or water lettuce. I've tried half a dozen times; it always dies in just a few weeks. I just buy a few plants in the spring, and this time of the year, I'm throwing out 10 pounds of water lettuce a week.

That's what I'm doing at the moment, especially the lettuce. I take out 2 handfuls AT LEAST just to make a hole so I can feed the fish. lol Just read Kenny's post, sounds like he'd be better with a pond. Keeping an aquarium takes talent, and 1 that I don't think I'll ever aquire. As for the ph....I'm developing a new ph chart, my tank looks like a cross between a snow globe and a cloudy white gel candle. <_<

Robyn what causes an auquarium PH to change. I understand the pond not so much the aquarium?

There really are too many factors to give an absolute answer. The pH can change due to the processes of live plants, bacteria, fish, microorganisms, algae, etc. They all have some impact, even if minute. The plants have the greatest impact. An aquarium without plants shouldn't change too much day to day or hour to hour. This section on my site tries to explain how plants (and to a lesser degree animals) effect the pH during different parts of the day due to the carbonic and respiratory cycles:
http://www.fishpondinfo.com/plants/algae4.htm#plants

Water that is low in hardness and alkalinity like my well water is more apt to have pH fluctuations because the bicarbonates that make up alkalinity buffer the water. Buffering is like a cushion to protect the pH. Imagine that you put a glass of water on your bed. If you put it between two pillows, then it's buffered. If you set it by itself, it's not. Now, push on the glass. You can see that the glass without the pillow buffer will fall over. That's akin to a pH crash up or down. Any little process or something can cause the pH to change more drastically when there is no buffer. I just made up that analogy but it sounds pretty good. So, for water with low alkalinity, I suggest adding baking soda. I do put some in my ponds but not my aquariums. I just don't have the time to add and monitor it with all my animals, tanks, and ponds.

You mean ME??!! well actually ive been asking for a pond for quite some time now and still dont have it :X lol....well actually my aquariums fine now!! hope you can get things balanced out!! BTW: i dont test my PH and my fishies are happier than ever now!!!