yes, take out all the sponges you can. they just trap your uneaten food, snail crap, algae and etc. Then they sit inside that dark canister with great flow and creates an orgy if you will for nitrates. Shagin is correct, that they WILL also suck up sand, even if you dont stir it that much.
I also did not have money for a sump setup (till now), so i worked with the canisters and purigen only. Then i move to an old Penguin 330 HOB (hang on back) power filter that i had from my freshwater days. Ive SUCCESSFULLY been using the HOB with purigen in one side, and Cheato Algae and live rubble rock in the other. I slide in a filter sponge after a water change or when i stir things up to catch the big junk that would normally pass over purigen. But remove it within 8 hours.
If your going to stick with canisters heres my opinion and recommendation. take it with a grain of salt:
- First, back off on feeding. (every other day is what i do, flake with brine or dry pellet, Frozen stuff like phytoplankton and mysis is more what i call an occasional "treat") It may not seem like you are overfeeding, but more times than not we are. Its fun to watch and fatten them up, but its more difficult to battle poor water chem in the long run. Most Detrius comes from you. and your feeding. If you limit the buffet, you limit the crap.
- Your going to have to water change often (maybe 10-12 days about 10%). Mix a batch of salted (RO/DI if you can) water up the night before and let it agitate over night with a spare powerhead or air stones/ bubbler. RO water will limit the phosphates you add to the tank. Phosphates = algae = nitrates and a vicious cycle of dying algae and new algae. Plus, detoxed tap water still has other impurities and metal. (Think about your plumbing? and what all that water is running through before it comes out your faucet)
-clean that canister a minimum of every 4-5 days. 2-3 days better. This becomes a pain... eventually, most canister operators break down and find something different (HOB or sump), not because they are all lazy, but mostly because every time you stop that canister, gunk flies out into the tank, you agitate the tank, fish are stressed = more poop, and you fire that thing back up and more gunk flies out.
** side note, im more convinced the majority of nitrate issues with canisters are from debris gunking up inside those ribbed tubes. and from operators not flushing them everytime they clean the canister. (Like me)
- make sure you have great flow over your rock work. It needs to be chaotic and random, but not blasting your fish across the tank. (Better flow = more biological filtering with your live rock and "good" bacteria). Waves in the ocean provide chaotic flow across rock work, add oxy to the water, and helps agitate the detrius from settling.
-Massive amounts of nitrate not only creates issues for fish, but it creates issues for the "good bacteria" you want to keep. It also limits coraline growth and over all ability to biologically filter the nitrates the way nature does in the reefs.
-even good bacteria eventually dies. more so if your water chem is off. So once they die, thats adding more problems to your tank. (I dose Seachem Stability 4mL with each new batch of water change). Just in case the bacteria in my live rock need some reinforcements.
-The most important thing i think i have learned is let that darn tank settle. Constantly changing things, moving things, cleaning things creates chaos. Its an ecosystem, it has to settle and balance out. think about the badass tanks on this site... how big they are... how many devices they have operating it... skimmers, GFOs, sumps, refugiums, automated lighting, auto wavemakers. While expensive, they also completely operate themselves which means the ecosystem can settle out.
My biggest mistake as a newb, (still consider myself that, compared to the other old dogs on RC) was constantly sticking my hand in the tank to fiddle, clean, meddle, test, and poke around.
Sorry for the rant. hah.
