Avoding Water Changes

[Thalamus]

Hello all

I am looking in to purchasing a rather large Marine Aquarium. I currently have a 30 litre tank, but the one I am looking at is 450 litres.

My question is, is there a way of completely avoiding 'traditional' water changes (purchasing salt water from a pet shop and adding it to the tank after removing a certian percentage of water) by purchasing additonal tanks and equipment?

My initial plan was to buy a RO unit, fill up a secondary tank with water, let the RO unit do its magic, on the tank of processed water, add salt to the desired level and then activate a pump to introduce the water to the main aquairum. This would be a manually activated procedure at the time of wanting to do a water change.

Your thoughts please?

 

[Anonymous]

I don't see how what you are proposing is any different than a "traditional" water change. You plan on making up a tank of saltwater which you will add to your display tank. I presume you will be removing the same volume of water from the display tank during this change.

You do not want to add salt water as your top off for your display tank. Is this what you are suggesting?

 

[Thalamus]

lol, by "traditional" I simply meant that "the way people do it with small tanks".

You are right, I am planning on making up a tank of saltwater which I will add to my display tank. BUT, can I use water from my tank to do this? Effectively recycling my tank water instead of introducing new water.

Water from tank > recycle > back in to tank

instead of

Water from tank > put in bucket and pour down the drain - Add water to the RO setup > introduce new water to the tank.

I suppose what I am trying to say overall, taking out of the equation evapouration, is there a way of making a tank completely self sufficent without introducing water from an external source?

 

[Anonymous]

Thalamus, forgive me if I'm misunderstanding you, but I think you might be laboring under a misapprehension about how a RO/DI unit works. It doesn't purify salt water (i.e. you couldn't use it to clean water you take from a tank during a water change). It's designed to purify tap water, producing much purer water, which you then add artificial salt (e.g. Instant Ocean) to. The advantage to this method over buying water from the store is that it works out cheaper in the long run.

 

[Thalamus]

Hey Ape,

Thanks for the clarification! - I like to make things more complicated than they orginally are!

So, my proposed RO/DI setup would require tap water, after which I can add salt and then it can top up my aquarium! - Is this common practice for hobbists who have large aquariums?

Is this how people generally set it up - Tank of tap water > RO/DI unit purfys > Tank of clean water > Introduce to tank (obviously after removing the desired amount of water from the tank)

I assume the above setup would be completely seperate from the normal workings of the sump. So the RO setup is run, as and when it is needed.

 

[Anonymous]

Hey Ape,

Thanks for the clarification! - I like to make things more complicated than they orginally are!

So, my proposed RO/DI setup would require tap water, after which I can add salt and then it can top up my aquarium! - Is this common practice for hobbists who have large aquariums?

What? No no no no no. What kind of water evaporates? Fresh water *only*. You can NOT replace fresh water with salt or you'll drive up the specific gravity to intolerable levels very quickly. DO NOT DO THIS. Mix up fresh saltwater, perform a proper water change. Don't try to cut corners doing this, or if you are, then limit the corner-cutting to fish that are bred in captivity, at the very least.
Do NOT try to filter saltwater through your RO/DI unit! Don't try to recycle the saltwater, either. It's been filtered as much/as well as it can be in a closed system (when you consider the volume of just one small cove compared to what you propose, 450 liters is woefully little water volume) already and your residents *will* need FRESH saltwater, to be changed out and added. Use the freshly filtered RO/DI to top off your sump reservoir at most.

So, to specifically answer your question, "...is there a way of making a tank completely self sufficent without introducing water from an external source?" Unequivocally NO, there is not. You are running a closed system.

 

[Anonymous]

Hey Ape,

Thanks for the clarification! - I like to make things more complicated than they orginally are!

So, my proposed RO/DI setup would require tap water, after which I can add salt and then it can top up my aquarium! - Is this common practice for hobbists who have large aquariums?

Is this how people generally set it up - Tank of tap water > RO/DI unit purfys > Tank of clean water > Introduce to tank (obviously after removing the desired amount of water from the tank)

I assume the above setup would be completely seperate from the normal workings of the sump. So the RO setup is run, as and when it is needed.

Just to be clear, the most typical set up is:

Using RO/DI filter, you make up enough water to fill the tank. You then add salt, testing salinity with a hydrometer (or, even better, a refrastometer, which is more accurate). After that, you add the sand/substrate if you're using one, then rocks etc.

Once it comes time for your first water change, you make up another lot of RO/DI water, probably in a large bucket/rubbermaid container. You then add salt (Instant Ocean or something similar) to make the water up to the same salinity as the tank water. The water needs to be aerated in the bucket with a small powerhead and heated to the same temperature as the tank. It also is best left like this overnight before use.

You then use the same procedure each time you want to change water for the tank, probably every week or every other week, depending on how much water you're changing each time.

Ask questions if that's not clear.

 

[Thalamus]

Thanks Guys for your responses!!!

We all got to start somewhere right? :p

Thanks for sharing your knowledge and putting me in the right direction!!!!!!

 

[Anonymous]

No problem, it's much better to ask before then after!

BTW, there was a typo above - it should read refractometer, not refrastometer. Worth investing in one if you can, as stable salinity (as well as keeping other conditions stable) is crucial for long term success, so you need an accurate way to measure it.