White substance(like salt) forming all over tank

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Discuss all topics related to freshwater and planted tanks.

Posts: 2
Joined: Wed Jan 21, 2009 7:36 am

White substance(like salt) forming all over tank

by Kylehen

I need some help please. I have a tropical tank that keeps losing water - I think through condensation. Anything I can do about that?

I have thought of connecting an air fan to the system - Havent quite figured out weather it should suck or blow.
Any thoughts on this would be appreciated.


There seems to be a crystal forming region in my tank. its everywhere really - but in some places more than others. Its very fine white crystals that keep on forming. Its staining the glass and has a very bitter taste.

How can I stop these crystals from forming?
How can I remove the build-up on the glass?

Some help here would be very much appreciated.

I may also have some pictures...

Thank you


Posts: 80
Joined: Mon Dec 01, 2008 8:20 pm

by vwfan79

Do you have a lid on your tank, evaporation will cause minerals in the water to crystallize on the glass....What kind of light are running, if they create too much heat it will increase evaporation and cause minerals to crystallize more rapidly....removing this build up requires some scrubbing, it does come off though.

Posts: 2
Joined: Wed Jan 21, 2009 7:36 am

by Kylehen

Yes, I have a lid, but there is a gap about the width of my hand and the length of my arm at the back of the tank ( It was bought with this gap though. Nothing has been modified)

Should I close this gap in the back?

I have a blue fluorescent lamp and it seems that the white substance is drawn to this lamp. Thank you for the heads up of hot lamps.... Ill check it out.

Are fluorescent lamps ok or should I opt for something else?

This white stuff is giving me a good beating. I have tried to scrub it with almost all household materials that I could get my hands on....it helps but it doesnt work. Isnt there some kind of chemical I can use.....I owe the rest to my arm.

What do you think about the Fan Idea?

Thanks for the response...Sure is much appreciated

Posts: 887
Joined: Wed Feb 13, 2008 8:33 pm

by Tmercier834747

as vw said its probably just mineral deposits left on the glass from evaporating water. closing the gap in your hood will cause the evaporation to occur more slowly and allow you to remove the minerals with water changes instead of with a scrubber brush. Or you could simply start buying reverse osmosis water (the way most bottled water is filtered now) to do top off's with as I'm pretty sure R/O is almost completely void of minerals and trace elements.

I'm assuming by 'blue' florescent you mean actinic. Generally in freshwater tanks (I'm assuming you're talkinga bout freshwater) the actinic lighting can encourage algae growth. You should try to find some 6500-10,000kelvin bulbs instead.

Fans and moving air around your lighting would only be beneficial for two reasons. 1. The light is throwing off so much heat its causing your tank to overheat which usually only happens in multi-bulb power compact, VHO, or Metal Halide fixtures. 2. Prolonging the life of your bulbs in one of these fixtures if it is giving off a LOT of heat. Other than that the moving air will just cause more evaporation.

White substance(like salt) forming all over tank

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