# Considering Refugium



## dsiple3 (Mar 4, 2014)

I am considering using a planted tank below my main tank to assist with water quality. Water changes *WILL* continue as before. But I have a few questions before I do this. The main tank is the one in my signature.

1) I want to use a DIY overflow to drop water into the tank and use a canister filter to return water to the main tank. The filter pump is rated at ~250 GPH. 
-A) Is this too much flow for a planted tank/refugium? 
-B) As long as I try to prevent plant material from entering the canister, is using a canister filter as a return pump an acceptable option? 
-C) Will I need a flow check valve if the power goes off and the return opening is slightly under the main tank water level? Basically, will it flow backwards through the canister? If so, 6" clearance from top of tank to water level is approximately 15.5 gallons (just over 10% of main tank volume).

2) I am not looking for a beautiful looking tank underneath, because it will be housed inside the stand under the main tank. However, my OCD tendencies may show up if things are arranged haphazardly. I want to use a sand substrate with plants in some sort of order (so I don't drive myself crazy when I have to go inside the stand for filter maintenance). The tank will not house any fish, only possibly in an emergency, and have a water height of ~15".
-A) What types of plants would work well to be in sandy substrate?
-B) What types of plants to have taller height in the back and shorter in front? (This is where I would go nuts with no plan to work off of.)
-C) Should I put some type of critter (some kind of shrimp, etc.) to help maintain some level of cleanliness? (I honestly don't want to have to feed both tanks everyday.)
-D) Will I need to put a layer of peat moss under the sand? Or would it just help if I did?

Any thoughts, comments, suggestions, critiques welcomed. I'll probably have other questions beyond these depending on answers, but I want to possibly get this project started and working (at least water flow) this weekend.

Thanks for your input.


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## Deeda (Oct 12, 2012)

The problem I see is using a canister filter to return the flow to the main tank. Canister filters have a minimum and maximum filter installation height and I think it is going to be difficult to operate it properly if the the level of water in the sump is only 15" tall. You would be better off using a submersible pump to return the water to the tank.


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## somebody (May 13, 2014)

I don't know about others bit the fluval 306's intake has a check valve on the intake strainer granted you trust it. I've shut down my cannister for maintenance and whatnot and never had a problem with water outflowing (weather it is and I just don't see it orbit truly isn't or not at all which is what we're looking for). I agree with deeda plumbing it just like a sump would prolly be your best bet plus there more information readily available if you need it 8 an emergency. That's the problem with custom diy, only you know how your system is set up and running and it will be a lot harder to find info in a pinch if needed. As for water flow I don't know the recommended rate of flow for one but there is plenty info out there to help you get started. Just remember, cause it's something I'm figuring out, putting a second tank below your display to work in conjunction with the display you have to account for evaporation and the only problem I see is water level dropping equally in both tanks (though not necessarily a problem) bit you would have to have a drilled aquarium, atleast to be safe. The hob overflow would work until the water level drops to the point the overflow stops working then you fill you display with the water from the planted tank.

So in conclusion my suggestion would be to plumb it like a normal sump/fuge filtration setup. That way you know how it works and it will be easier into understand incase of problems and avoid turning the area around your tanks into a pond. Another thing to think about would be a hob fuge. Simple plug and play mindset.


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## joescaper1 (Feb 14, 2013)

1. I agree with Deeda, a submersable pump would be best.
1A. 250 gallons per hour is less than a coffee mug a second, it should be OK.
1C. Just put the return a half an inch below the top of your overflow or build in a siphon break.

2A. There are so many plants that will work, so just Google freshwater refugium plants, then figure out what is available in your area.
2C. Using live plants, you will probably have snails.
2D. Mineral Mud is commonly used in refugiums.

As a side note; with overflows, evaporation does not result in water level drop in the main tank, only in the sump. In the main tank water will always remain at the height of the overflow.

Also, you will need plenty of light for the plants.

Joe


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