# White deposits in my aquarium...



## desico (Mar 3, 2011)

I'm hoping someone out there can help me figure out what is going on in my tank.

I have a well established:
125 gallon freshwater aquarium
pH=8.0
KH=130ppm
GH=280ppm
running CO2 because it's a planted aquarium

I have this white dusty, slightly gritty deposit on everything. I can wipe most of it off my plants. Some of it seems stuck on. It's almost like the calcium/lime deposit you get at the top of the tank only it's everywhere.

Has anyone ever experienced this or know how to remedy it? I think it has something to do with my really hard water but not sure why. I tested water straight from my tap this morning and the GH & KH are identical to the tank water.

Thanks!


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## Thoth (Mar 16, 2011)

What kind of plants are having the problem?


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## desico (Mar 3, 2011)

Thoth said:


> What kind of plants are having the problem?


It's not just on the plants. It's on the rocks and the glass as well so it's not really a plant problem. It's more a water problem.


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## SinCrisis (Aug 7, 2008)

Did you have large calcium/lime deposits on the tank before you filled it? It might be that parts of it are dissolving and falling off, causing it to land on your plants. Run a polishing pad in your filter, see if that helps.


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## desico (Mar 3, 2011)

I found this on another planted aquarium forum. The person sounds like they had the same thing as what I have (only I have it on the rocks and glass as well) - they figure it's lime scale below is a response that they received:

_"This is called biogenic decalcification. Certain plants (like Egeria, __Najas, __Vallisneria, and __Ceratophyllum) are capable of utilizing the bicarbonate ion as a carbon source. They take in bicarbonate, HCO3-, keep the CO2, and leave behind OH-. In strong light, enough alkalinity is created at the leaf surface to precipitate calcium carbonate, CaCO3. This process can also raise the pH up to potentially dangerous levels."_

Has anyone heard of this? What do I do? I'm going to check my pH tomorrow (I just did a 50% water change yesterday).

SinCrisis: the tank had some limescale around the top but I try to clean it off as best I can every week when I change the water. I don't think it's falling from there - I don't see much in the water itself just on everything... I'll try the polishing pad though, just in case. I also thought I might get some peat pellets to put in my filter and see if I can soften the water somewhat.


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