waste water treatment idea

[CamDAX]

Would it be possible to process our waste water from water changes to a point where we could reuse it again in our tanks? Kinda like a sewage treatment plant for our tanks.

I was thinking if you where to put the waste water in a 55gal. drum that circulates through a sump say out in the sun with a skimmer and macro algea. The water slowly goes through a de-nitrification reactor into another 55gal. drum for storage. Could this potentially clean the water to the point we could reuse it?
I understand this would be a system in of it self and would need to be full of water at all times.

Of course the tank would be more depended on adding trace elements through dosing. Unless you added them post water change.

 

[boxfishpooalot]

Could work. But I think most are trying to do this already with ats and macro algae no?

 

[CamDAX]

Ya people are trying but aren't they having trouble? I figured since people are getting zero detectable nitrates out of a coil de-nitrification reactor. Your water would end up being that clean. I've heard of people putting them on their tanks but they always say it doesn't make much of a difference and that the water coming out of it is clean.

Since one usually does 10% water changes every week on a 75gal. thats 7.5 gal/week. Not much but by the time it all trickles through such a reactor you would have a few days before you need to do another water change. Heck you could do 20% and still get away with it. A small system could handle a big water volume. Just 2 55gal. drums and you got a 40gal/week capacity. 15gal. less because you have to leave some water in it to keep the de-nitrification reactor alive. So say a 200gal system doing 20%/week or a 400 10%/week.

 

[philosophile]

You would need to replace calcium, and other trace elements if you did this, but in principle it would work. Algae will add different chemicals to the water that may turn the water a slight green/yellow tint too. But that can be removed through skimming. Evaporation water would need to be replaced. Anything that falls into the container would need to be filtered out if you're keeping it outside for free light.

you'll still need to make some salt water to replace salt lost in creep and skimming.

I think generally, it isn't worth the effort.

 

[muttley000]

I believe some large public aquariums do this, but problem is in the things you can't easily measure if I remember correctly. How about reusing your reef's water in a predator or fish only tank?

 

[Randy Holmes-Farley]

This method will reduce nutrients in the salt water, but may make depleted trace elements and accumulated organics worse, and won't do anything for the major ions that may become depleted or elevated (such as potassium, chloride, etc.).

 

[pledosophy]

If you wanted to set up such a biological filter, why not just attach it to your tank all the time? It would keep your water cleaner overall so you would see the constant benefit. Then you could dose for elements you needed.

 

[CamDAX]

If you wanted to set up such a biological filter, why not just attach it to your tank all the time? It would keep your water cleaner overall so you would see the constant benefit. Then you could dose for elements you needed.

I understand some people do this but the problem I see is that something about the re-circulation causes the over all benefit to not work as much as it could if it was a separate system creating Zero Ammonia, Nitrite, Nitrate recycled water.

This method will reduce nutrients in the salt water, but may make depleted trace elements and accumulated organics worse, and won't do anything for the major ions that may become depleted or elevated (such as potassium, chloride, etc.).

Over time don't the accumulated organics degrade into ammonia? So the water would need to sit for a few days then right?
Ya you would have to add trace elements back into the system.
Couldn't you add the major ions back?



I know it sounds like a lot of work. I just hate that I have to throw out a bucket of saltwater a week instead of recycling it. Getting rid of all the junk and adding some good stuff back in.

This really is all just a thought experiment for me. Like could one keep a saltwater reef tank going in the event of an apocalypse or keep a tank without having to worry about weather or not you can get salt that is meant for a saltwater tank. I understand it would be possible if your near the ocean and could just pump in sea water. But what if you can't get sea water, like where I live the water temp and SG is too low?

I guess I should have opened with that...

 

[Randy Holmes-Farley]

Over time don't the accumulated organics degrade into ammonia? So the water would need to sit for a few days then right?
Ya you would have to add trace elements back into the system.
Couldn't you add the major ions back?
.

Many organics, and in particular, those I'd want to export with a water change, will not degrade sufficiently in a few day to be useful. Some organic in the ocean have been accumulating for decades and are very resistant to microbial degradation.

Adding major ions only works if the tank is deficient, not if it has too much of one.

Personally, I think it would be better to experiment with no water changes than to try to fix used tank water.

 

[arnoldrew]

I understand some people do this but the problem I see is that something about the re-circulation causes the over all benefit to not work as much as it could if it was a separate system creating Zero Ammonia, Nitrite, Nitrate recycled water.



Over time don't the accumulated organics degrade into ammonia? So the water would need to sit for a few days then right?
Ya you would have to add trace elements back into the system.
Couldn't you add the major ions back?



I know it sounds like a lot of work. I just hate that I have to throw out a bucket of saltwater a week instead of recycling it. Getting rid of all the junk and adding some good stuff back in.

This really is all just a thought experiment for me. Like could one keep a saltwater reef tank going in the event of an apocalypse or keep a tank without having to worry about weather or not you can get salt that is meant for a saltwater tank. I understand it would be possible if your near the ocean and could just pump in sea water. But what if you can't get sea water, like where I live the water temp and SG is too low?

I guess I should have opened with that...

I get that it's a "thought experiment," but post-apocalypse one would have a lot more to worry about than a fish tank.

 

[pledosophy]

I understand some people do this but the problem I see is that something about the re-circulation causes the over all benefit to not work as much as it could if it was a separate system creating Zero Ammonia, Nitrite, Nitrate recycled water.

I have zero ammonia, nitrite, and nitrate in my system now with my recirculating filter on the tank. I am actually worried now because my phosphate is too low and starting to cause bleaching so I pruned my refugium back.

It is very possible to do in a closed system, not nearly as hard as you think.

 

[shermanator]

Would it be possible to process our waste water from water changes to a point where we could reuse it again in our tanks? Kinda like a sewage treatment plant for our tanks.

The Natureef system does this. It's an off-line tank that uses carbon dosing and huge bacterial counts to remove nitrate.