pro's and con's of evaporation

[kospaintball]

Can anyone tell me specific pros and cons of evaporation in an aquarium?

 

[Adalius]

Only real pro is that it cools your tank by evaporative cooling, but that's only really a pro if your tank is running hot to begin with.

Cons? Reduction in volume results in an increase in any and all dissolved/dilluted chemicals in the tank, including dissolved organics, nitrate, nitrite, ammonia, etc. Then there's the pain in the butt factor that you have to continually top off to get the tank back to original volume (or run an ATO).

 

[burning2nd]

Cons would be reduced water volume, Increased salt level

PRo's assist with natural exchange of gas's (feel free to step in here scientist people) Aid's in cooling

 

[Eric]

In a large tank with auto top off I don't think there is a down side, since you are replenishing the water as it evaporates there are no real changes in water quality or salinity.
In a nano it may be a little more noticable due to smaller volume of water but then again if you keep it topped off it shouldn't be a problem.

Pros are as mentioned heat and gas exchange.

 

[Jeremy0322]

The gas exchange is pretty important, which is accelerated via evaporation. This is because at the end of the nitrogen cycle the final product is nitrogen gas, which then leaves the water into the air via evaporation I believe, so the more evaporation you have the more effective your nitrogen cycle in the tank will be.

Taken from this site...

Aquarium Nitrogen Cycle and cycling. Methods for ammonia, nitrite removal.

"Ammonia is assimilated in more than one way. Plants (such as Hornwort) and algae can assimilate ammonia and ammonium directly for the biosynthesis. The remaining bulk of decomposed byproducts are utilized by bacteria in a process called nitrification. Fortunately Ammonia does not last long in a healthy aquarium environment. Nitrifying bacteria such as Nitrosomonas quickly break down ammonia into less toxic Nitrite (NO2). During this process, specific species of nitrifying bacteria strip the ammonium of its hydrogen molecules as an energy source. Oxygen molecules are then affixed to the stripped nitrogen, forming the oxide nitrite (NO2).
Another group of bacteria (Nitrobacter ) utilize the enzyme nitrite oxidase that is then responsible for converting nitrite into nitrate (NO3). This nitrate can either be used by plants as a nutrient source, or can be further broken down into nitrogen gas (N2) through the activity of anaerobic bacteria such as Pseudomonas .
It should be noted, that without oxygen (nitrification is an oxidative process), none of this process can take place. "

 

[Adalius]

Nitrogen, and other gases, will leave the tank just fine if there's enough other agitation going on, either via powerheads breaking up the surface of the tank or any other place where the water is allowed to tumble, like in a FOWLR tank against bioballs, or inside a skimmer.

Evaporation helps the degassing, but is hardly a requirement.

 

[Frankie]

The gas exchange is pretty important, which is accelerated via evaporation. This is because at the end of the nitrogen cycle the final product is nitrogen gas, which then leaves the water into the air via evaporation I believe, so the more evaporation you have the more effective your nitrogen cycle in the tank will be.

Taken from this site...

Aquarium Nitrogen Cycle and cycling. Methods for ammonia, nitrite removal.

"Ammonia is assimilated in more than one way. Plants (such as Hornwort) and algae can assimilate ammonia and ammonium directly for the biosynthesis. The remaining bulk of decomposed byproducts are utilized by bacteria in a process called nitrification. Fortunately Ammonia does not last long in a healthy aquarium environment. Nitrifying bacteria such as Nitrosomonas quickly break down ammonia into less toxic Nitrite (NO2). During this process, specific species of nitrifying bacteria strip the ammonium of its hydrogen molecules as an energy source. Oxygen molecules are then affixed to the stripped nitrogen, forming the oxide nitrite (NO2).
Another group of bacteria (Nitrobacter ) utilize the enzyme nitrite oxidase that is then responsible for converting nitrite into nitrate (NO3). This nitrate can either be used by plants as a nutrient source, or can be further broken down into nitrogen gas (N2) through the activity of anaerobic bacteria such as Pseudomonas .
It should be noted, that without oxygen (nitrification is an oxidative process), none of this process can take place. "

Excellent post Jeremy! I see you have learned a lot in the past few years of school
kospaintball, this is one of those things that just is. It is like us breathing. There is no stopping it. But you can promote it to benefit your aquarium with the above statement.

 

[Jeremy0322]

Excellent post Jeremy! I see you have learned a lot in the past few years of school
kospaintball, this is one of those things that just is. It is like us breathing. There is no stopping it. But you can promote it to benefit your aquarium with the above statement.

haha, thanks Frankie, nice to see the almost 20k a year is paying off! LOL

 

[Exo]

The gas exchange is pretty important, which is accelerated via evaporation. This is because at the end of the nitrogen cycle the final product is nitrogen gas, which then leaves the water into the air via evaporation I believe, so the more evaporation you have the more effective your nitrogen cycle in the tank will be.

I am not sure I agree with this. Below is a nerdy explanation why ::turntable

Nitrogen gas (or for that matter CO2 or Oxygen) are exchanged based on the partial pressure of the dissolved gas in the water versus the atmosphere. Since the total pressure at the water/air border (interface if you want to be fancy) is essentially the same (1 atm at sea level) we can assume that the partial pressure equal the concentration

So if the nitrogen gas in the tank is a higher concentration than the air it will tend to leave and vice versa

The rate of diffusion you can basically think of as how far and hard the nitrogen has to work to leave. We can make the rate the fastest if we create little drops of water so the gas doesn't have to travel very far or we can make the water turbulent so it has a higher surface area and makes it easier for the nitrogen to leave if you will.

Evaporation isn't the cause but it is increased by the same factors so they look related but aren't. However evaporation is heavily affected by temperature and gas exchange is not nearly as affected (although temperature matters some). Evaporation is also affected by humidity which gas exchange is not.

At least I think this is the case. To me there isn't a benefit to evaporation unless you need the cooling. Anyway don't mean to argue but hope this clears it up a little.

 

[Jeremy0322]

You dont ever have to be sorry for arguing, thats the only way that the actual answer is reached most of the time. Im not exactly sure on this one, but the explanations that I can think of would be that either as evaporation is increased the rate at which the nitrogen gas is brought out with the water molecules would increase. I would think that the water coming out of your tank is not "pure" water, it would have to be bringing something along with it. The other thing I could think of really has nothing to do with evaporation, but now I want to know the answer to the question. Nitrogen gas is used by the plants in your aquarium as food, so hypothetically your plants would take it up and as an end product you would get oxygen gas, which could then be used by your fish or would eventually leave the aquarium. Either pathway oxygen would take it would not be harmful

 

[Adalius]

I'd have to agree with Exo on this one, kind of goes with what I posted above. And as for the water leaving your tank via evap not being pure, well, yea, it is pretty pure. That's why evaporative distillation produces pure water, sure they evap it 3-4 times, but even the first pass has it potable, or damn near. So anything that was evapping out with it would have to be marginal.

 

[kospaintball]

i don't have an issue with the evap, i was just curious, other than the raise in sailiniy and such if there were any pros/ cons to the issue.

 

[Willie McDaries]

OK,Jeremy...you guys are talking way above my edgamakayshon,but it sounds good...glad to see you're paying attention in school