Evaporation and Humidity

[Banana Man]

Hi,

I'm in the process of ordering a custom built 500L (130g) rimless tank with no lid. I'm a bit worried that humidity will be a problem and I will have to replace massive amounts of RO water every day. Does anyone else run a tank with no lid that can tell me how much water they lose to evaporation every day and if they have any humidity issues?

The LFS said they would retro fit a glass lid on the tank for free if I find humidity to be an issue but I'm starting to think it would be better to just get it done now. I'm getting a shallow tank and really like the no top rimless look so really want to give it a go without first though if possible.

Thanks!

 

[pkc]

Evaporation is directly related to a variation in temps.
Evaporation is the way in which water can change from a liquid to a gas and this achieved by molecules colliding and transferring energy to each other until some near the surface have enough heat energy to escape.
You only get humidity if the room is relatively sealed where your aquarium is stored.
If your water is 24c and your room temp is 30c you get quick evap,if your room is 15c and your waters are 24c you will get quick evap as well.
I don’t have lids as they restrict some gas exchange that helps stabilize PH.
Get it with lids and make up your own mind up later on as to whether you will use the lids or not.
I have a plastic frame that fits my aquarium and monophiliment netting in this as my lid so no one can jump out.
Just remember only hydrogen and oxygen evap, everything else including the salt stays behind.

 

[pkc]

Sorry I forgot to put this in, if there is high humidity, there is near no evaporation as well.

 

[Banana Man]

That's interesting. So in the winter time if I have the central heating set to the same temperature as the tank I would get very little evaporation.

 

[ErinCahir]

It depends on how humid it is where you live. You're going to have some evaporation. The drier your climate, the more you're going to get.

 

[Aquarian]

In my 36g I loose between 1/2 to 1 gal of water a week to evap depending on the weather conditions.

 

[kbuser92]

And in my 20 I get roughly a gallon or more in a week. Do NOT get a glass lid.

 

[FishyReef]

I don't have a lid on my tanks and I replace about 1g a day in my 90g, more during the summer when its hot. You don't want a lid on your tank as it restricts oxygen exchange and cooling through evaporation (which is a very effective way to keep tank temps stable).

 

[Banana Man]

Where do people get all the replacement water? After reading some other info I'll likely be losing 10L per day!!! I thought it would be more like 1-2 per day. I'll go broke buying water or spend the rest of my life making my own!

 

[Sidekick41]

I too loose about 10 gallons a week on my 55 Gallon. I purchased a RO/DI filter to make my own. It's a little pricey up front but save you time and money in the long run.

 

[FishyReef]

Where do people get all the replacement water? After reading some other info I'll likely be losing 10L per day!!! I thought it would be more like 1-2 per day. I'll go broke buying water or spend the rest of my life making my own!

I have an ro/di to make my own water from the tap. Honestly it doesn't take me more than a few hours a week, particularly if I'm just making top-off water. This past weekend I spent about half a day making 7 5g buckets worth of water, but most of the time I just fill up about 10 1g jugs over a few hours and they last me all week for my tanks (90g, 10g, 20g).

 

[Banana Man]

How long does it take to make 10 gallons of RO/DI water?

 

[RockStacker]

How long does it take to make 10 gallons of RO/DI water?

It depends on your RO/DI unit.

Taking a 75GPD system for example (the most commonly used kit):
75 gallons per day (24 hours) = 3.125 gallons per hour.
So this unit would make 9.375 gallons of RO/DI water in 3 hours.

That is what it would produce "on paper". There will be variations based on the following:
1. The condition of the prefilters/membrane.
2. The water pressure at the supply end.
3. Water temperature.
4. Impact of ramp up time or what they call "short cycle".

 

[FishyReef]

My unit is a 90gpd unit. I find the first bucket or so is pretty slow but it gets much faster the longer the water is turned on. I also find temperature greatly impacts it. If I run really cold water it takes forever, and if I run hot water I can fill up a gallon jug in about 5m. Technically I'm supposed to run it with cold water, but I usually do it somewhere in the middle.

 

[PsiStar]

I have ro/di with automatic top off. It saves a lot of messing around.

I think it depends on what is in the main tank as to whether it is covered or not. I have had 2 fish that jumped out as well as snails that have climbed out ... freaky coming into the room of a morning & you accidentally kick a "rock" across the floor. Oh, wait! What! That's a snail!! This happened more than once.