Critique my water change idea please

[vinstr]

Hello all
I am setting up a new 120gallon tank and am trying to make water changes as quick and easy as possible. My tank will be upstairs with a 30 gallon sump and 30 gallon Rubbermaid garbage can downstairs.

The setup is below and "normal operation will have the overflow from the tank come down and into the garbage can which will be drilled with an overflow into the sump which has the protein skimmer and return pump to tank.

Both the sump and garbage can will have float valves fed with RO/DI water for top off. When I want to do a water change. I will turn Gate Valve A above the garbage can which will divert the overflow directly into the sump. The garbage can will still be filled with water so I will turn on a small pump in the bottom of it and send all the water into my sink and down the drain. The empty garbage can will now fill up with new RO/DI water. I will add salt and have the small pump just recirculate the water inside the can until it fills up and the salt is mixed. I will then turn gate valve A back to sending the overflow water into the garbage can again which will continue normal operation.

Does anyone see any issues with this?? Thanks in advance.

 

[vinstr]

https://drive.google.com/open?id=1H6z-ZsDU7ggvLKK3_Jskvd9X5UbgzokE

 

[vinstr]

Can anyone see my image? I am having trouble posting it, sorry.

 

[mcgyvr]

I can see your image just fine..

And your plan should be fine but the garbage can won't need its own ATO system.. Unless you just meant thats the one you use during water changes only..
Its level should not fluctuate from evaporation..

 

[vinstr]

Thanks Mcgyvr and yes, it would really only be there to refill the garbage can during a water change so I can make fresh salt water in it. If I use the float valve I can just let it fill on its own, not have to worry about it overflowing and come back later in the day once its full reopen the gate valve. I'll keep that float valve at a level just below the overflow.
Thanks for the reply!

 

[JamesZebedee]

I like this plan, only question I have, is will food debris accumulate and rot in the bottom of the garbage can? Perhaps you could hang a filter sock under the inlet pipe.

I'm actually planning on something similar. I want to plumb my water supply direct to the ato in the sump. I'll then use the osmotic reservoir to dispose of and mix water.

 

[vinstr]

James- Yes, but that is part of my plan. Anything big will fall to the bottom and not go through the overflow into the sump. But when I do my regular water changes, I think I will use a siphon to get the water out of the trash can instead of having a small pump in the can which will allow me to suck up anything at the bottom of the can each time. Since there will be nothing else in the can I can easily get it all and it will less bioload on the skimmer.

 

[der_wille_zur_macht]

It's a good plan, with the obvious caveat that you won't easily be able to vacuum the display or sump during water changes. Depending on how and where detritus settles, that may or may not be a problem.

The overflow from the trash can to the sump should be as large as possible, definitely larger than the drain from the display to the trash can. You don't want things to get backed up there.

Depending on the drain style, you may find that you get some weird performance when you swap the valves to do a water change. Some drain styles don't like plumbing changes.

An important consideration will be the water level in the trash can. Ideally, you want the refill level (the point at which it refills to via the RO/DI supply) to be the same as the level it's at when running. Depending on the drain configuration, etc this may be a challenge you have to work through via adjusting plumbing, etc. Even if you're using a float valve in the trash can for the refill function, I would consider putting a valve inline with it. This way, you can manually shut if off when you're not doing a water change, which will prevent any issues if the float switch fails, gets stuck open, etc., during normal operation. Shouldn't ever happen, but I like having shutoff valves anywhere I'm using water straight from an endless source (ie an RO/DI unit).

Might want to consider putting a tee and valves on the small pump in the trash can. Have the line from the tee redirect right back into the trash can. This way, you can use the same pump to mix the new saltwater as you use to empty the trash can. You'll need a heater in the trash can too, obviously.

 

[der_wille_zur_macht]

James- Yes, but that is part of my plan. Anything big will fall to the bottom and not go through the overflow into the sump. But when I do my regular water changes, I think I will use a siphon to get the water out of the trash can instead of having a small pump in the can which will allow me to suck up anything at the bottom of the can each time. Since there will be nothing else in the can I can easily get it all and it will less bioload on the skimmer.

You could do that. Although a pump is easier. Just turn it on and you're done.

Another idea - you could run a siphon from the display, emptying right in to the trash can. Do this immediately before water changes. The garbage will get dumped into the trash can. You could even just run it into a temporary filter sock hung on the lip of the trash can, to catch the junk you suck up. You wouldn't need to adjust plumbing or anything, do this with the tank running in "normal" mode and you will basically just bypass the overflow drain.

 

[vinstr]

Thanks all -great ideas all around and i will be incorporating some of them. But I will not be vacuuming the display ever. I will have the nice pink sugar fine sand which i had years ago. I never once vacuumed that tank in 10 years it was set up and had awesome coral growth and no algae once I started using ro/di.

 

[on the spot]

Only thing I might try would be lifting the garbage can to drain off the bottom. Gravity drain to the sink.

Would make adding the salt a little tricky though. maybe add a drain off the sink stub to lower the barrel a few feet?