# Vallisneria and pH fluctuation??



## Swamp Chick (Apr 9, 2010)

New and loving the forum!
I am setting up a 90 gal planted discus tank. (No discus yet! pH problems)
Plants are growing like crazy! (Vallisneria spiralis, crypt red wendtii, E. tennellus, E. bleheri, Anubias nana, Red tiger lotus, sagittaria subulatta)
Fish: 9 neons, 3 bristlenose plecos, 6 otos, several ghost shrimp; all healthy
Light 1.5 watts per gal. At this time I am not adding CO2, but reading up on the pH fluctuation that I am observing, I may not have any real alternative.
KH in tank is 3, GH 4 to 5 (My tap water KH is 0, GH 1, pH 7.0)
My tank pH is about 7.5 in AM, then rises to about 7.8 during light hours.
I have read that vallisneria can cause biogenic decalcification, and this may be causing the high pH and pH rise. Should I get rid of the val? It's gorgeous.
Any suggestions for stabilizing my pH?
Thanks!


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## Bert H (Mar 2, 2004)

What kind of substrate are you using? I ask because your tap kh and gh are both lower than your tank's. Are you adding anything to the tank fert wise?

Eco-complete substrate is known to raise kh and gh (to a lesser degree). Typically in a few months this effect diminishes.

In planted tanks, it's fairly common to have pH fluctuations between light and dark. I have never kept discus, are they that sensitive to that small a change? Lots of folks here have kept them, perhaps some will chime in.

BTW, welcome to apc!


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## Swamp Chick (Apr 9, 2010)

Fluorite substrate.. I have been adding some buffering agents to increase KH. Read that extremely low KH could contribute to pH swing. Then of course had to add buffers to reduce pH. Supposedly pH swing of .3 or more can be detrimental to discus. I would like to get my pH stable somewhere around 6.8.
This is my first high tech tank. It's been set up since mid January, the plants are doing great, but I do not feel comfortable buying di$cu$ (LOL!) 'til I get the pH thing under control!


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## Swamp Chick (Apr 9, 2010)

Many thanks to everyone here on APC who referenced or recommended D Walstad's book. It arrived yesterday.. I read 'til 1 AM!
What a fantastic resource! It has really has changed how I am looking at my current water problems!
I will post pics of my 90 g tank soon (still sans discus!)
When I set up my 125 g, it will definitely be El Natural!


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