Natural Sponges

[BzztYeow]

I had a couple of natural sponges laying around in an old hermit crab cage - i think my smoking killed the crabs .

They are about half fist sized and i thought that while my tank was a bit overcrowded (waiting for the larger to arrive) i would throw them into the tank as a media for the cycling bacteria.

They sit on the back of my 20 gallon- over a bubble wall- kept in place by a piece of driftwood pinning them to the back wall.

The large tank arrived a few days ago- i set up the substrate, filter, heater, and other mess and threw two kenyi's in there to get the Nitro cycle going. I also put a couple of glasses filled with substrate into the new 60 gal tank. The ammonia spiked an cycled to under .25mg/L within two days, but the nitrites skyrocketed above the scale of my test kit.

Then i tried something odd. I took two of the three sponges i had in the old tank and squeezed them multiple times in the new, larger tanks. It made them cloudy for a couple of hours, but the next day-BANG the nitrites and ammonia are zeroed! I though i made a mistake in the testing so i triple checked it- but the dang tank seems to have cycled within 1 week!

I'm wondering if anyone has experience with natural (dead) sponges in freshwater tanks. Do they rot and release nasties or is having a couple of sponges laying around in you tank a good idea?

I haven't read anything about sponge filters that use NATURAL sponge, they all seem to use a manufactured sponge material (which i assume would not rot). I was amazed by the nitrite reduction in the new tank that wringing these natural sponges produced. I was almost half convinced they were just causing problems in the old tank with their decay.

Is there a danger I am missing with these natural sponges? They have only been submerged about 1 month in the old tank. They seem to be great way to help a new tank cycle, but i don't wan't to keep them submerged if they will cause problems later.

Thanks for any advice!

 

[Dragonscales]

I think it may have more to do with the bacteria colonies living in the sponges than the sponges themselves personally.

 

[daudy_dojo]

hey i have some of those sponges cause i used to have lil hermies (died cause they were like 5 years old ) i wanted to use one of those sponges on that DIY sponge filter! do the rot away??

 

[BzztYeow]

No answer yet here-

Dragonscales- i also beleive that the benefit from these sponges comes as a medium for bacteria since the sponges themselves are long dead by the time i had introduced them.

I was wondering if there were any known harmful effects associated with leaving natural (dead) sponges in a tank.

 

[Dragonscales]

I am only hazarding a guess here, so don't take it as truth, but I would think that they will break down eventually, possibly adding ammonia, etc to the tank.

There are two reasons for this, the first is that they are organic and the second is that if they were fine over long time use then they'd be used in filters instead of synthetic sponge.

Like I said though, I wouldn't have a clue as to the validity of these points and someone feel free to set the record straight if you know. In the meantime though I would be careful and keep a close eye on them as well as testing their structural integrity every so often by squeezing and stretching (not too much though) them. First sign of decay or falling apart then take them out quick smart.

 

[BzztYeow]

That's exactly what i did Dragon. I squeezed these sponges out weekly just to prevent any rot, but found a bit of debris (sponge frags) every time i did this. I got rid of the sponges when i moved my cichilds from their patheitic 20 g to my current 60 g.

I think if you use them as bacteria media, you can cycle a new freshwater tank damn near instantly with them, but i wouldn't recommend leaving them in a freshwater tank.

FYI- i never actually ran into a problem with them, they just kinda got in the way in the new tank. They may be a valuable addition to your tank, although you will have to do that testing yourself