Could you run a nano tank off a larger tank? As if they were a single system, but in only one direction (large to small)?

[ebeltran]

I've got a 135g system that is pretty well established after a bit over a year, and I was curious: If I wanted to start up a pico or nano tank, 5-50g, could I run it off the larger tank? As in, rather than constant new saltwater changes in the pico (I've seen people say up to 100% water change every couple days), instead just periodically pulling really well balanced, healthy water from the large tank to replace in small one. It seems like, while the small system cannot sustain the sort of ecosystem that would keep the water stable and healthy, the large tank would necessarily be creating water that was more stable for longer, even if placed in that smaller system. The goal would be: 15g water change every other month (my current routine), but instead of dumping that still-pretty-healthy-water down the drain, use it to replace 15g in the smaller tank (where the water quality deteriorates more quickly). Does this make sense? Any obvious pitfalls? Totally harebrained?

 

[Court_Appointed_Hypeman]

In a new tank you will be dealong with either non colonized surfaces, or surfaces colonized by a completely different makeup. This can mean there will be significant differences in how the microbiome of the water column will affect the nano from the larger tank.

However, I do this with my holding system and no issues so far. I would say just expect to go through cycles all the same unless it's getting very alive rock in it, and remember that the ubcolonized surfaces will be prime realestate for any nuisances from the water column of the old tank. Doesn't mean it's a bad idea, just that using a constant supply of well balanced water used from another tank is not by any means set it and forget it.

It does have a chance of causing issues, but you'd already have the ability to change course and use fresh salt water if needed anyway.

 

[Dburr1014]

I have the ability to hook up my Hospital tank to my auto water change system from my main display. Every day I change one gallon of water from the main display and instead of dumping it it goes directly into my Hospital tank. I just have to remember to take out a gallon of water from the hospital tank everyday before the ATO goes for that day.
So it can be done it's just how to implement it on your system.

 

[blecki]

You'll always be replacing water in the smaller tank with water that is already depleted of some resources. Not great for, say, a frag tank - but perfect for QT. I do this - drain QT; fill QT from display; top up display with new water - but only when nothing is actually in QT so I don't accidentally violate quarantine.

 

[Ef4life]

I tried it before, the no3/po4 levels of the big tanks water was causing algae issues in the nano is what I figured. I stopped doing that and replaced with new slat water instead and the algae growth slowed down. If it was fairly established with a nice amount of corals I think the algae issue would have been way less

 

[hart24601]

@xiaoxiy does this for his QT and it works great.

 

[MnFish1]

I've got a 135g system that is pretty well established after a bit over a year, and I was curious: If I wanted to start up a pico or nano tank, 5-50g, could I run it off the larger tank? As in, rather than constant new saltwater changes in the pico (I've seen people say up to 100% water change every couple days), instead just periodically pulling really well balanced, healthy water from the large tank to replace in small one. It seems like, while the small system cannot sustain the sort of ecosystem that would keep the water stable and healthy, the large tank would necessarily be creating water that was more stable for longer, even if placed in that smaller system. The goal would be: 15g water change every other month (my current routine), but instead of dumping that still-pretty-healthy-water down the drain, use it to replace 15g in the smaller tank (where the water quality deteriorates more quickly). Does this make sense? Any obvious pitfalls? Totally harebrained?

The same analogy is a sump. So - the answer - yes.

 

[Court_Appointed_Hypeman]

I tried it before, the no3/po4 levels of the big tanks water was causing algae issues in the nano is what I figured. I stopped doing that and replaced with new slat water instead and the algae growth slowed down. If it was fairly established with a nice amount of corals I think the algae issue would have been way less

This is an important point. I have almost no spare nutruents in my water column so I have no issues there. If you have elevated nutrients, I would at least dilute it out with fresh salt water

 

[xiaoxiy]

@xiaoxiy does this for his QT and it works great.

Yeah. This is exactly what I do for my QT. It’s 3 gallons in volume and gets 100% daily water changes from my main system. Seems to work well, but it did take a couple months to settle in. For some reason I couldn’t keep acros in it for the first couple months even though I could keep the same strains fine in the main system.

 

[ebeltran]

Great thoughts, all - thank you! I was planning on seeding the smaller tank with some live rock that has been cooking in the sump of the large tank for the past year. I know there's some issues with removing the biology there from the tank, but its probably less than 5% by weight of even just the rock, so should be ok. As far as this being 'the same as the sump, so ok' my thinking was that there is constant interchange of water, bacteria, etc, with a far more robust filtering system in between, rather than a one way trip to a tank with basically no filter (a HOB... maybe?). But either way, seems ok.

As for flora, the whole idea came from my recent addition of lighting to support some acros, which are growing like weeds now, and its negative effect on my devils hand, bubble coral, and some others. So I was thinking of moving those low-requirement softies to a lower-light environment. Given the acros thriving in the DT, my thought was that there would be enough 'left over' to support the softies second-hand.

 

[fish farmer]

I've got a 135g system that is pretty well established after a bit over a year, and I was curious: If I wanted to start up a pico or nano tank, 5-50g, could I run it off the larger tank? As in, rather than constant new saltwater changes in the pico (I've seen people say up to 100% water change every couple days), instead just periodically pulling really well balanced, healthy water from the large tank to replace in small one. It seems like, while the small system cannot sustain the sort of ecosystem that would keep the water stable and healthy, the large tank would necessarily be creating water that was more stable for longer, even if placed in that smaller system. The goal would be: 15g water change every other month (my current routine), but instead of dumping that still-pretty-healthy-water down the drain, use it to replace 15g in the smaller tank (where the water quality deteriorates more quickly). Does this make sense? Any obvious pitfalls? Totally harebrained?

Are these connected systems? Or separate? It sounds like you want to use your old WC water in a smaller system which seems fine. At the same time you said that the water in the small tank would deteriorate quickly....I can't see where an every other month water change on the new tank whether it is fresh water or old water would matter, unless you are planning more frequent changes on the small tank, but just back and forth with new and old.

 

[Steve Fast]

I run a 50 gallon tank off the system for my 500 gallon tank. I drop the overflow to the same sump and have a pump returning water from the sump too.