[aquasalt]

....nothing?

Why bother replacing your bioballs with rock ruble if you're packing sufficient live rock in the tank and are skimming? Isn't the natural filtration process is taking place with or withou rock ruble or bio balls?

Having rock ruble in a "simple sump" (i.e., no baffles, etc.) just increases the risk of particles ending up your pump.

Let me know your thoughts?

[pogodzib]

For some strange reason, having bioballs in a tank with a ton of LR still seems often end up causing high nitrates issues. A common thought is that the bioballs are too efficient at converting the nitrite to nitrate and it doesn't give the LR enough time to convert the nitrate to nitrogen gas. Another thought is that since the nitrite is being converted away from the nitrate-nitrogen conversion, the nitrate doesn't have an option of being converted directly to the gas before it gets into the water column. Who knows, maybe it is the fact the bioballs trap detritus so there is more nitrate being produced. Either way, I think their is very few, if anyone, truly knows the reason why, but removing bioballs from tanks with a lot of LR often results in a better water quality. LR rubble does the same thing as LR since it has anaerobic places where nitrate can be converted to nitrogen gas, although, IMO, it also creates places for detritus to get stuck and break down into the tank water.

[aquasalt]

So then what are the advantages of having bio-balls? Why bother with them in the first place?

I had to read your reply a couple times (sorry...Monday, 5 o'clock!), but am not sure I understand your position regarding the above. Should the sump contain Live Rock Ruble or is this superfluous?.

[NATIVEVAMAN]

The only use I see for rock rubble in a sump is to fill an over under bubble trap.Its sharp edges and irregular shape make it a natural for this task.I dont see bio balls as being up to this task.

[patrick1234]

if you go with bioballs you need to have a prefilter spunge to stop any build up on them
but most ppl ether go with a wet dry ie:bioballs
or a fuge/sump ie:liverock and ruble

[aquasalt]

I am currently running my tank with bio-balls, but was going to replace them with rock ruble. Then someone challenged my thinking on the ruble. Can I just take out the bio-balls, forget the rock ruble and run the system without either?

[patrick1234]

id not do rock ruble but big live rock pices do you have a skimer?

[patrick1234]

and how much rock is in the tank?

[NATIVEVAMAN]

If you have a skimmer and micro bubbles are not a problem and you have lots of live rock I wouldnt worry about it.

[aquasalt]

I have a skimmer and i'm guessing about 100 to 120 lbs of LR in my 90 gallon. I haven't updated my thread in a while, but you can see pictures in the "90 gallons of saltwater life" thread. We added another 10 lbs of live rock last weekend.

Would you take all of the bio-balls out at once or remove them slowly over time?

[NATIVEVAMAN]

I would take them out slowly to make sure you dont knock off any of that goo hanging on them and check your nitrates the day after.

[pogodzib]

Take a couple handfuls of bioballs out per week until they are all removed. I don't have any rock rubble since I have close to 3 Lbs/gal. of LR. My order of preference between these choices would be just Live Rock, LR rubble, and then bioballs as a last resort. With any of those options, you'll want to have a good protein skimmer to pull gunk out of the water column.

[aquasalt]

Do you use a sock to filter debris?

[pogodzib]

A lot of people do, but I don't since there has been a couple studies that say that if a sock isn't cleaned every couple days, the detritus buildup in the sock starts dissolving anyway so they don't do much good. As a whole, using a sock is probably a good idea as long as it doesn't get clogged, but I'm just too lazy to use the filter sock and my tanks have always done good without them. If my overflow water went through either bioballs or rock rubble, I would probably put a sock on though.