View Full Version : Hello fellow reefers i have a serious question

11-30-2012, 06:01 AM
My question is who has ever had a problem with there aquariums causing mold in there house after 1 year of your aquarium being set up from evaporation? I would appreciate some good responses to this question. Thank you my fellow reefers

11-30-2012, 06:44 AM
a good dehumidifier works, or venting fans

few question to help your question out.
size of tank?
how much space is between the top of the tank and the ceiling?
is the tank open or close top?

11-30-2012, 12:00 PM
Yes. And I solved this problem by installing an HRV in my house. No more condensation, no more humidity, no more mold.

If you do a google or forum search for "HRV" you'll see that they are quite popular.

11-30-2012, 01:28 PM
You may find that a dehumidifier will pull water out tank. Good circulation is key

11-30-2012, 01:59 PM
I have a Costco.ca dehumidifier in my sump/furnace room that pumps the water out to a drain. It doesn't smell. I have an ATO on the salt mixing tank and for the make up water tank (a 5 gallon pail). So far it's been good but I've only had the 100+50 tank going since August. Before that I had a 20gal tank that had a covered canopy so I never had issues. My 100dt has no cover but I've noticed that I am getting more condensation on the windows as it has got colder outside.

11-30-2012, 03:21 PM
The severity of the problem will depend on your total water volume, what kind of lighting you'll use (because it influences evaporation) but yes, this is a common problem and in Alberta the best solution is a HRV. Other options that will work but not as efficiently are installing a bathroom fan or other venting, or a dehumidifier. I found a dehumidifier to be noisy, inconvenient, costly to run and the dehumidification effect to be localized to whereever the unit was sitting whereas the rest of the house still suffered from excessive humidity.

A HRV ("heat recovery ventilator") trumps a bathroom fan in that it IS a bathroom fan basically but replaces the air being taken out of the house with fresh air from the outside, and uses heat exchangers to preheat the recovered air to something like 95% efficiency (rather important if it is -20 outside).

The whole house benefits too. Even if I quit my tanks I'll always have an HRV in my house, they are very useful overall.

11-30-2012, 03:52 PM
Ventilation/air circulation is key in mold control, humidity is only part of the problem. Any area of your home that does receive adequate air circulation is vulnerable to mold growth. If you have forced air heating you should examine your air flow and circulation throughout the home, more often than not homes lack air returns in all rooms or don't have proper gaps under doors. Ducting from the furnace is also often done poorly resulting in uneven air flow distribution. Furnaces and fans can be undersized and filters can be clogged all causing circulation issues. Furnace fans can also be programmed to run more often for better circulation and don't forget to check humidifiers you may have installed, many humidifiers are out dated and use float valves that constantly fail and require attention to prevent them from constantly adding water to the air.

HRVs can be added to exchange stale air from inside with fresh air from outside while recovering the majority of the heat. A good addition to any home and these days it's often a standard in new homes. However typical installs usually result in the HRV piggy backing on the existing ventilation system. Running extra ducting may be required to solve air circulation issues in addition to humidity.

11-30-2012, 04:06 PM
What is the suggested humidity percentage for a household.

On eBay I got a bunch of hygrometers off eBay for $4 each and spread them throughout the house. My humidity has plummeted to 22%


11-30-2012, 05:00 PM

I do not have any visible mold that I am aware of in my basement where my tanks are. I had two high efficiency heaters installed a few years ago that bring in fresh air from the outside into the venitlation as part of their design. Would this act a bit like an HRV in this respect?

11-30-2012, 05:09 PM
I would think no, but maybe your furnaces just simply provide enough volume turnover to prevent humidity buildup. Being that they are high efficiency, theoretically they cost less to operate than mid efficiency, and therefore you might get more air turnover per dollar spent on heating than, say, I do. In my case the HRV gives me air turnover without having a huge impact on my heating costs. There is a bump of course but much smaller than it would be without an HRV.

11-30-2012, 05:24 PM
My fishroom had a bathroom fan on a humidistat and a seperate fresh air intake to feed the room. I had the room set to 40% humidity. My tank wasn't running very long and after tear down I did find mold on a wall where some containers/boxes were either touching the wall or very close to it. Perhaps my fresh air vent and the fan were too close together and I wasn't getting great airflow. Perhaps this solution no matter how well setup isn't enough I can't say for sure.

12-01-2012, 03:27 PM
This really is one of those topics that deserves a sticky as it, your health, is just as important as the rest of reefkeeping. Healthy home and body plays a role in the health of your tank; have to take care of the caretaker(s).

12-01-2012, 07:33 PM
Since the temps dropped this week, I haven't been able to see out any windows. We need to look into something to deal with this as well.

12-09-2012, 04:31 AM
Mold has been around for millions of years it ain't going away even though you don't see its there...i work construction and see mold in house with out fish tanks... I don't know why people freak sooo much(real money maker for me :biggrin:)..sure it has been linked too some health problems but that's why we have a immune system...i personally run dehumidifier/air purifier... IFind occasionally mold on wet windows but whip it up disinfect area a month later its there again...im not worried about it we all breath in mold spores from time too time lol

12-09-2012, 02:12 PM
Since the temps dropped this week, I haven't been able to see out any windows. We need to look into something to deal with this as well.

Take a trip to your local hardware store and buy a package of shrink wrap film and double sided tape. Thats what we have to use on our windows otherwise they would be so covered with condensation and ice we wouldn't be able to see out of them for 7 months of the year.

Mould is an issue in the place that I rent as well. But not necessarily because of the tank. With the tank alone the humidity in here right now is only about 40% but as soon as we boil something in the kitchen or take a shower it jumps to 60% because there are no exhaust fans in any of the bathrooms or kitchen. There is also only R 24 in the ceiling and patches in the wall with no insulation at all. Plus I've been told that this house was once used as a minor grow-op so the mould problem existed before we even moved in.

So in addition to shrink wrapping and the occasional diluted bleach cleaning we keep the furnace fan running constantly to disperse the humidity evenly throughout the house. We also keep all of the furniture an inch or so back from the exterior walls to allow air to flow behind them.

07-19-2013, 01:26 AM
I'm journey men sheet metal worker and the best way to deal with humidity by large aquatic system is an hrv ideally put an outlet in the room the aquarium is in just like you would a bathroom and put it on a timer so it runs 6 hrs at least during the day broken up by a few time slots. 2 hrs in morning 2 in the afternoon and 2 in the evening and because it regains the heat as it changes air it won't add a lot to the heating bills in the winter

The Guy
07-19-2013, 02:48 PM
Good air circulation in your home is the key to control air quality, make sure you keep air moving and address dead air zones with circulation fans. If you can afford central air it will help with lowering humidity in your home, but keep your furnace fan running and keep that air moving.

08-08-2013, 06:49 PM
I find Calgary extremely dry, even now in the summer my basement where my 250 G tanks is situated the RH is only 41%, upstairs on my main level where I have a 100 G tank it's 36% on average.

I would imagine if your tank is in a 'fish room' or a smaller foot printed area then it could be a problem, I just never thought about mold due to high humidity. I would agree, air movement is critical to ensuring good air quality.

My basement windows are completely clear and I would estimate my evaporation rate is about 12-14 Gal per week judging by the size and replenishment frequency of my ATO tank.