What do you do to keep nitrate levels down

[C.Mydas]

Good post GaryP!

Thunderkat and demodiki: Regarding the husbandry of rays
"If an undergravel filter is not used, the depth of subtrate material should be kept to a minimum (5cm [about 2in] or less). This is especially true for very fine sand, which can readily become anaerobic."

"The larger grades of crushed coral and dolomite can irritate the animal's ventral surface and cause bacterial infections."

-Aquarium Sharks and Rays: The Essential Guide to Their Selection, Keeping, and Natural History by Scott W. Michael (pg 52-53)

Sharks and rays ARE vastly different than the bony fish we keep...even their gills and skin omit ammonia (bony's do to...but sharks and rays are a lot larger so have more of an impact). They really do require a special tank and wont thrive in a 'regular' reef tank. Not to say that reefkeeping techniques should not be used...b/c they should, their are just different issues and problems that need to be addressed.

As a side note angels ARE NOTORIOUS for picking at elasmobranch's (sharks and rays), repeatedly biting them which may cause and infection and kill the animal.

Compboy: What type of ray?

[Thunderkat]

Check out plenum systems C. Mydas. Kk, thx

[C.Mydas]

lol..I know what plenums are..and personally Ive never seen anyone be able to maintain a plenum successfully and definately wouldnt recommend it to beginners. Besides that though..plenums are not recommended for elasmobranch's.

1. The biggest concern being that sharks and rays often disturb the substrate which would release all the gunk in a plenum into your tank.

2. With these kind of animals biological filtration is severely inadequate. Live subtrate is OK for a small shark or ray..but they dont stay small. Heavy 'outside' the tank filtration is needed. IE: pressurized canister systems, wet/dry's, fluidized bed filter etc.

3. sharks and rays are easy to overfeed and have a propensity to regurgitate..rapidly increasing the waste in a tank and most 'live subtrate' tanks wont have adequate nitrifying bacteria to break down the sudden 'extras.'

If you have a plenum ...great...I dont think its wise...but different methods work for different people. However, the care of the animals comes first, and plenums or DSBs are not the best solution for a tank with animals that will most likely send the substrate flying and release all that 'gunk' into your tank...not a healthy situation.

[Thunderkat]

Well, with plenum systems you add a screen 2 inches above the bottom to prevent burrowing critters from getting to the bottom layer. It is not very pretty but it works. The plenum system is not without its problems, I have excessive coralline algae growth, it grows like crazy on my glass, it sounds great at first until you have to start scraping it to see. I think it is a result of high calcium levels caused by the plenum. When I get to my next duty station I think I will add SPS when I have my tank set up again. Sharks would make a mess but they would still make a mess in a barebottom. Also in a plenum system you do not have a growth of anarobic bacteria, I think you would have to use mayo or something similar to get that to happen in a aquarium anyways, microaerophilic bacteria do grow plentifully in a plenum and that is what does all the reduction in wastes. I have heard that heavy skimming is required and oxygen levels can drop to dangerously low levels at night. This has not been observed by me because I have a fuge with cheato with 24/7 lighting and have a good skimmer on my tank. The plenum system is a BAD idea though if you like seeing stacks of live rock, I have grown partial to that in my fuge and nano and love seeing all the growth on it so will probably put a shelf in my next tank to keep the sand uncovered and get a large stack of live rock. The trick is though to make it not look tacky.

[GaryP]

Don't let Instar see your comments about not running a successful plenum sytem. It'll take hours to read his reply. You thought I was bad!

[compboy521]

Thanks for all the good information.
I don't know for shure if I'm going to keep the sting ray. Yes he cool but he dosn't really go a long with other things that I want to do.
I have a friend that wants him, he has keep them before.
I'll be shure to go out and get more live sand ASAP. I'm also doing research on how to start a refugium, I just have gotten started on one but it is in the plans for the very near future.

Again Thanks for all your help

[C.Mydas]

No prob..sorry for our tangent :roll

No bare bottom is not a good idea for sharks and rays...like I said they need a sand bed...a shallow one is better.

[Thunderkat]

I started thinking about a plenum and sharks and realized it would not be a good idea because you would get the copious coralline algae growth and would have to be sticking your hand in the tank to clean it off all the time. I like my fingers :lol

[C.Mydas]

lol. :w00t