# Large resin ornament - water problems later?



## DKRST (Jan 11, 2011)

How much trouble am I in with a large piece of resin "driftwood" in my 55 gallon? The piece probably holds a 1/4-1/2 gallon of water and I'm certain the artificial branches of the decoration are going to be stagnant areas. Of course, I didn't know about possible issues until I joined this forum...

The tank is stocked already and planted. I'd really prefer to not move the piece. I'm afraid moving it will drain the water from these potential stagnant areas into the tank when I pull it out (the branches/legs drain through tiny 1/8" holes).


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## lorax84 (Nov 3, 2010)

Was this made to be an aquarium decoration or just something you would like to use in your aquarium? I have a couple of pieces of resin "driftwood" that were made to be aquarium decorations and they all have holes in them to allow for water circulation. The only thing I have to do is make sure I suck out any debris inside when I do a water change. Maybe a picture would help people determine if your piece will be a problem or not.


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## DKRST (Jan 11, 2011)

It was purchased at Petsmart and is for aquaria. There are small openings, but the branches ("legs") are basically about 1" diameter (2-8" long) dead ends. These legs each have a tiny hole in the very bottom, but not enough to allow circulation when stuck into the substrate. Had I known, I would have enlarged some of the openings, allowing better circulation. I'll try to post a picture tomorrow.


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## lorax84 (Nov 3, 2010)

Depending on how long the ornament had been in the tank I would probably just take it out. Unless it has been there for months it should be alright. If you are really worried you can siphon the water inside the ornament out through one of the holes before taking it out.


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## DKRST (Jan 11, 2011)

Good idea, I'll just need to get a more narrow siphon hose than I have. I'll take the ornament out and drill some larger & additional holes for water circulation. I'll just have to make sure I make them all on the side facing the back of the tank!


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## Amethyst123 (Mar 4, 2011)

You could take the ornament out and rinse it in your waste water when you do a water change. Presumably you're changing the water with enough frequency that if you rinse your fake driftwood with every change, or even every other change, it won't build up too much nastiness, even if there isn't much circulation inside the thing itself. 

If you do drill larger holes, you could create more current inside the ornament by sticking a bubble stone inside it. 

One additional thing, which you may have already thought of... If you drill larger holes, make sure they are eithertoo small for the fish to try to swim through or big enough for your fish to swim in and out of easily. Just barely big enough to swim through could cause damage if they try it. You might even be able to make some realistic-looking "knothole" type things for the fish to use. That would definitely add to the circulation.

My motto about ornaments - as long as it's safe for your fish, have fun and be creative!


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## DKRST (Jan 11, 2011)

Good ideas. I don't think I want to pull it out each change. It's large (about 18" long, 11" wide and 12" tall. Barely fits into the 55, and then I have to rotate it just right. It's awkward to remove and I have live plants starting to grow around and under it. Also because of the plants, I'd prefer to avoid airstones, but that's an excellent decorative idea! Might do that as long as I don't make the silly thing float!

I had not thought about potential entrapment, other than I already have that issue the way it has two larger openings at only one end. I can just see my pepper corys getting stuck down one hollow tube. I want to drill some holes large enough to serve as a possible shrimp refugia later on (keep them away from larger chomping fish?). I'll sand the edges of each new opening to make it smooth and see what happens. 
Thanks!


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## Amethyst123 (Mar 4, 2011)

DKRST said:


> Good ideas. I don't think I want to pull it out each change. It's large (about 18" long, 11" wide and 12" tall. Barely fits into the 55, and then I have to rotate it just right. It's awkward to remove and I have live plants starting to grow around and under it. Also because of the plants, I'd prefer to avoid airstones, but that's an excellent decorative idea! Might do that as long as I don't make the silly thing float!
> 
> I had not thought about potential entrapment, other than I already have that issue the way it has two larger openings at only one end. I can just see my pepper corys getting stuck down one hollow tube. I want to drill some holes large enough to serve as a possible shrimp refugia later on (keep them away from larger chomping fish?). I'll sand the edges of each new opening to make it smooth and see what happens.
> Thanks!


You're welcome! 

I have an airstone and plants attached to the same ornament, a resin "stone" shelf. Doesn't seem to be a problem, but it might with some types of plants. With an ornament that size, it would take an awfully big airstone to make it float! If you're worried about it, you could attach some rocks or something else heavy with aquarium-safe acrylic.


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## Byron (Mar 7, 2009)

If I've understood this thread correctly, leave it alone. There is no issue.

The "water" isn't the concern anyway, it's the substrate under the item. Substrate that is "open" at the surface will have a regular flow of water down and back up again. Aerobic bacteria colonize this substrate and interact with organics, plant roots, and water to break down the organics into nutrients for the plants. Oxygen is obtained both from the water and the plant's roots.

Where this water circulation does not occur, due to a chunk of rock or wood on the surface, the substrate under it becomes "dead" or "anaerobic" because little or no direct oxygen gets to this area. This is not at all bad though. These areas will be colonized by anaerobic bacteria that either do not use large amounts of oxygen or they can create their own oxygen. Anaerobic bacteria release toxic gases, especially hydrogen sulphide, which in excess can rot plant roots and become a problem for fish, and encourage algae. But anaerobic areas also allow nutrients to be more readily available and more easily assimilated by plants because it prevents oxygen from binding with the nutrients. Denitrifying bacteria colonize the surface and obtain oxygen from nitrite and nitrate to produce nitrogen gas which usually escapes throuogh the water surface.

The more plants you have, the smaller the anaerobic zones will be. As plant roots spread, they release oxygen, even under rock and wood. Plants like the larger Echinodorus species have very extensive root systems that will work their way throughout the substrate.

I have a lot of chunks of wood and some rock in my tanks, and in 20 years I have never experienced any problems from anaerobic areas. I recently read one botanist's view that anaerobic conditions were actually more beneficial than aerobic conditions for plants. Having a mix as most of us do certainly seems good. I wouldn't disturb these spots under wood and rock; it will significantly alter the conditions and that could really be trouble.

Byron.


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## DKRST (Jan 11, 2011)

Byron - thanks for the clarification! I thought it was the water trapped by the larger resin ornaments that everyone was concerned with. I didn't realize folks were talking about substrate dead zones under the pieces.  Makes perfect sense now. The actual substrate "footprint" of my resin piece is pretty small, so I'll certainly follow your recommendation and quit worrying. Good info from you, as always. Thanks again.


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