Could Dead Coral be used like a sponge filter?

Discussion in 'Filters and Filtration' started by Creekwalker, Jan 9, 2013.

  1. Creekwalker

    CreekwalkerValued MemberMember

    I have a fairly large piece of very porous coral in my freshwater tank. I have been reading about sponge filtration and was wondering if i drilled a hole into this piece of coral and inserted an air tube, would it eventually act like a sponge filter? Possibly the air would just come right back out the hole, but that could potentially be sealed.

    Perhaps i don't understand how coral is made, maybe there are not a bunch of tiny tunnels in this piece.
    Will bacteria grow on it anyways over time without the addition of air/water flow?

    I have a 55 gallon tank, that has been up and running for about 50 days, still finishing up the cycling process. I'm concerned i don't have good enough filtration. I purchased a kit, and it came with the Marineland 300 bio-wheel filters (two wheels). I added a bag of bio-balls to one side of the filter a couple of weeks ago, been meaning to place a sponge in the other side (in addition to the filters with carbon in them).

    The piece in question is in the center of the tank pictured below.

    Last edited by a moderator: Nov 23, 2018
  2. AnthonyC4C

    AnthonyC4CWell Known MemberMember

    Welcome to fishlore! I figure I would throw up some info but still wait for others with more experience with everything you are asking.

    Corals, like shells, is composed of calcium carbonate. the fear is that carbon and calcium will disociated in water and change water chemistry. You use a 10:1 water:bleach you should be fine. Soak it for 10 , 15 minutes. Rinse well, and if you are worried about residue, soak in water over night, changing the water out a couple if you wish. Other than that I would try drilling it could possibly break apart your coral.
  3. AnthonyC4C

    AnthonyC4CWell Known MemberMember

    Very Nice Tank Too!
  4. monkeypie102

    monkeypie102Well Known MemberMember

    I don't believe that would work, cool idea though, bacteria (BB) will build up in it regardless just not as much as it would in a filter. you could still drill a hole and add an air tube, but it would just be for looks not really serving any use... but you do risk breaking the sponge if you do decide to drill.
  5. kinezumi89

    kinezumi89Fishlore VIPMember

    It definitely would at the very least house bacteria, but as Anthony said, it's usually not advised to keep coral in a tank unless you're trying to raise your KH, GH, or pH (maybe, not sure if the pH would change). Also, if it was in a saltwater tank, it may be leaching salt into your tank. I have tons and tons of coral because my parents used to do saltwater tanks, but I would never consider putting it in my tanks. (I have high enough KH and GH.)
  6. 3aquariums

    3aquariumsValued MemberMember

  7. OP

    CreekwalkerValued MemberMember

    Thanks for the replies. I've only been testing using an API freshwater master kit, which does not check for KH or GH. I guess i need to get those tests too. I've been able to stabilize my pH at 7.0 with this freeze pH at 7 additive, otherwise it would be ~8.0.

    So if i understand what ya'll are saying, it's that i may need to remove all the coral and go a different route for decor, due to the increase in KH or GH caused by the coral. I'd be fine with that if necessary, the kids can start rock hunting. I wanted to go with some drift wood anyways, but my parents brought all the corals for us to use at Christmas time. The also brought some pieces of petrified ferns which are not in the tank, but i see those in the LFS so i assume they would be okay.

    My tank is still cycling. I've been doing daily 40 gallon water changes for over two weeks, but have now been able to skip a day before Nitrites show up in my testing so hopefully i'm getting close to being done.
  8. OP

    CreekwalkerValued MemberMember

    That link confirms that I'm under filtering. I have 55 gallons and my filter is rated at 350 GPH, or ~ 6 times tank volume per hour.

    I'm still trying to figure out the concept of biological filtration. As i understand it i can only sustain as much bacteria as the Ammonia my fish/food are producing. So at some point i can have more media than is being utilized by bacteria to live. And also at some point i would imagine the water flow through a filter would be too fast to allow the bacteria to eat everything in the water. So what is the balance point? Do i need another identical filter or would some other type work, like an air driven sponge filter?

    I intended to make this work as is, and then in the future drop some money on a nice canister or sand tube thingy's.

    One thingy i like about the sponge filters is i can buy a cheap battery driven air pump to run one in a power outage.
  9. kinezumi89

    kinezumi89Fishlore VIPMember

    No more of that pH altering stuff!! :;smack There is nothing wrong with a pH of 8.0; mine varies 7.8-8.2 depending on the season. Your fish are used to the pH, and constantly fluctuating it is more stressful by far. Don't listen to websites that say a fish "needs" a certain pH. Some fish need a certain pH to breed, sure, but fish can adapt to a wide range of pH levels if acclimated slowly enough.