# Aquarium Evaporation & Mold



## twg (4 Nov 2015)

Hi everyone,

I have an open top aquarium which I regularly top up due to the evaporation which is absolutely fine.

The issue I am seeing in the room where the tank is located is spots of mold that have collected on some of the walls. These were never present prior to the aquarium being installed (6 weeks ago) so I am understandably a little suspicious that the tank may in fact be the cause of the issue, or atleast contributing towards an area of the house which may be prone to any extra moisture (the house is a 100+ years old).

I just wanted to see if anybody else had any similar issues caused by open top aquariums? And how you tackled the problem?

I have a de-humidifier running at the moment but if the problem were to get worse I may have to consider a custom lid or a possible overhaul to a cold water setup to reduce the evaporation rate.

Appreciate any advice/experiences you may have, cheers. 

Tom


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## jagillham (4 Nov 2015)

If you don't mind the look of it, a glass or acrylic top is going to sort that right out.

Is it an outside wall? If so, check the guttering above it. Could be rain coming down the wall. Also you may want to consider ventilation in the house full stop, open an upstairs window a little for some time each day (even if you had no tank!)


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## aaron.c (5 Nov 2015)

All depends on your house really.  Mine is pretty drafty and has an open fireplace in the room, so I don't find any build up of mould.


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## ian_m (5 Nov 2015)

Its because it is now winter and walls are colder thus will collect condensation leading to mould, especially in older solid wall houses.

You need to
- Heat the room more.
- Dehumidifier
- Insulate the walls.
- More ventilation.
- Tank cover.

My mate suffered mouldy wall behind his tank (despite a cover) in his old 1890's house, in the winter. Mostly cured by moving the tank away from the wall, finally cured by putting 3mm polystyrene under the wall paper when redecorating. In his new house (1970's) condensation/mould has not been an issue in all the locations his tank has been placed.


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## Konrad Michalski (7 Nov 2015)

Have you had cavity or loft insulated recently? My house was always dry and stupid me decided to go for the government schemes and insulated cavity and loft. Since then I'm struggling with mould. I suspected that fish tank could cause it but fish tank is downstairs and mould in the bedroom upstairs so it looks like my house is over insulated.


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## ian_m (7 Nov 2015)

Insulation wont make moisture worse, but what does do is reduce ventilation. A friend suffered really bad moisture and associated mould when his house was insulated and double glazed. He survived for years with a dehumidifier that had to have its waste plumbed in it generated so much water until he drilled and added "trickle vents" to his wooden double glazing. Just adding these vents in all the windows cured the house moisture issues and dehumidifier no longer needed.


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