Protein Skimmer, Bio Balls, Live Rock/Sand

So I have a 12.5 gallon aqua euro tank, it came with bio balls, I currently have I believe 15 pounds of live sand and at least 13 pounds of live rock in there. Bio balls are currently running in the built in "sump" in the back of the tank. I just recently read that bio balls may not be necessary, is this true? Do I NEED a protein skimmer? The occupants of this tank include 2 damsels (3 spot, and 4 stripe), 1 randall's goby, a mantis shrimp, various corals, and some snails, any suggestions/recommendations? Also since I'm reasonably new to the saltwater trade, where does the oxygen supply come from since from what I'm told air pumps should not be used with coral? I mean does my mantis need an air pump? I'm sorry if these are dumb questions...

 

you should use that blue or white filter floss to filter the water before it falls on the bio-balls.keep to much stuff from getting on them and turning into a nitrate factory.The return that comes back to the tank should aggitate the surface to give a good gas exchange to oxygenate the water. No bubbler.

 

+1 to above.

I like bio balls provided they are not submersed, water needs to be trickled over them and mixing with air to permit the beneficial bacteria to grow. The process of moving the water to and from your tank is generally enough to aerate the water column.

Skimmers are an effective means to eliminating dissolved organic compounds from your tank, which give rise to nitrates. It also aids in oxygenating your water by raising dissolved oxygen. I personally would not set up a tank without one, but that’s just me – many people have highly successful systems absent of a skimmer.

BTW - welcome to the forum !!

 

if it is infact a mantis you have you may not want to get to attatched to your fish n inverts.they can nd have been traind to be fish safe, snails nd crabs are another story. you may have a pistol shrimp wich r sometimes confused.

onto your question...you can go skimmerless if you can do 1 of 2 things.A,lots of small water changes nd smaller feedings or B be very luckey lol...my gf thinger has a 14biocube up for 2 years no skimmer or water changes.

 

well it's def. a mantis, it's a Lysiosquillina Maculata, he's being kept in there until I get a 40 acrylic for him . But in the back of these nano tanks there isn't much room so where would I even keep a protein skimmer if I didn't want a sump outside the tank? and since there's a hood on it I can't exactly get a hang on :/. Also so is the consensus to keep the bio balls, they are fully submerged in the back of the tank with the carbon and filter pads, should I just clean them regularly to make sure nothing "bad" is growing on them?