Live Rock Rubble in Sump, or Not?

nickbuol · Feb 13, 2013

I have a 120 gallon FOWLR tank that is about to get its first fish this weekend after their long stint in the QT. Anyway, I have a 2.5" aragonite sandbed in the tank, and about 140 pounds of live rock in the DT. Is there any real purpose to having live rock rubble in he sump?

My sump has basically 2 compartments. One where the water comes in through a filter sock and then gets skimmed with the skimmer. The heater is also on this side. The other side has about 5-6 inches of live rock rubble and then a small egg-crate "box" around the return line area just to keep the rock away and water flowing. The rock rubble is just the smaller stuff that I got when I bought the tank from the previous owner. He didn't have any rock in his DT and had all of it in a much larger sump (I only purchased the tank and the rock from him) so he didn't care about size. The rubble isn't tiny like pebbles, but more along the lines of almost the size of baseballs.

Is this small rock rubble really doing much positive for me or would I be better off in giving it away locally to someone and saving the space for something else?

I figure that I should make any adjustments now instead of after the fish go into the DT if possible.

nytegti · Feb 13, 2013

the rubble will give pods a place to thrive without being picked off in the DT. I keep ~10lbs of it in my 20L sump for exactly this purpose

Fatmike92 · Feb 13, 2013

Yea I think it is an awesome idea to keep live rock in the sump! It's really helps out!

Bigdaddy · Feb 13, 2013

how much should be kept in the sump and should it be small peices or large ones ?

nickbuol · Feb 13, 2013

So is it more for pod reproduction? I've heard some people complain about the rubble taking space and not providing much benefit with enough live rock in the DT. Oh, the sump is a 40 gallon breeder split pretty much in half with the two chambers. I didn't know if there was any reason to put something else in there since the live rock in the DT should be doing enough of the biofiltration. I might put a bag of carbon in from time to time, but that shouldn't hurt the live rock any. I don't plan to get a carbon/GFO combo, but if I ever did I would just need space for the pump that feeds the reactors.

So maybe I am all set as is for a while. Although my tank has been set up for almost 3 months now (without fish, but I've been feeding it every other day to keep a bioload going) and I see no pods. A did see what looked like a couple of baby nassarius snails, and the rock had bristleworms, but I've decided to keep them since they get into the nooks and crannies and aren't too big. I also have 3 hitchiking mushrooms/polyps (again, I'm not into corals. Love the tanks that people have with full reef setups, but for me it will be FOWLR+3 mushrooms LOL) that are doing really well actually, and water parameters seem to be great. Just no pods...

Greg@LionfishLair · Feb 13, 2013

If you're running FOWLR, and don't need the space, any extra LR is a benefit. We're exclusively FO now, in fact, we're pretty much exclusively keeping Scorpaeniformes, which can be large bioloads on their setups. To that end, besides running lots of LR, we also run live macro algae in our setups, which aids in water quality, looks nice, harbors pods, and gives the fish another area to rest in.

The pods will show up eventually. If you want to boost their production, you can feed your tank live Phyto every so often. It won't hurt your water quality, and will give the pods some food. Our dwarf lionfishes and waspfishes all hunt pods between meals.

nickbuol · Feb 13, 2013

Do you put the macro algae in the sump with the rubble? I've toyed with doing something like that, but I realize that it takes a LOT of macro algae to have an effective refugium, so the algae would just be mainly for more pod space.

ReeferBob · Feb 13, 2013

Macro-algae is great in the sump. Get a PAR38 bulb (on a timer) (I have an LED PAR38 that was on sale for $16 at Cosco) and some macro-algae and load it up. Great for pods and a natural phosphate/nitrate sponge. Also can never have too much rock. If you've got the space, add some rubble.

nickbuol · Feb 13, 2013

I've heard that in order to obsorb enough phosphate/nitrate it would take a LOT more macro algae to be effective. Maybe that is a myth. I was originally going to go with just macro algae in that half, (thus the main reason for my eggcrate "box" around the return pump intact), but more and more people at R.C. were telling me to scrap the macro algae because you need like a massive 80 gallon refugium or something crazy in order to pull enough nutrients.

It is the back-and-forth information of this hobby that make it worth the time once you figure it out, but a pain in the butt to get there sometimes.

nickbuol · Feb 13, 2013

So with a 2 chamber sump, is the water flowing slow enough for macro algae to pull enough out of the water to grow? The water is moving via an Iwaki WMD-40RLXT Pump rated at 1200 GPH (before plumbing of course).

fragmatic · Feb 13, 2013

nickbuol said:
So with a 2 chamber sump, is the water flowing slow enough for macro algae to pull enough out of the water to grow? The water is moving via an Iwaki WMD-40RLXT Pump rated at 1200 GPH (before plumbing of course).

It is my understanding that those who run algae scrubbers run a fairly high flow over them. So that says they actually need the flow like you would find in a sump. However, I run a separate refugium and my rock rubble is in it with my algae sheets. I don't like having to clean out from under the rubble when I do a sump clean out. I do some of my my water changes (about twice a year) from the sump and completely shop vac it clean to avoid any build up of junk.

By algae sheets I am referring to three sheets of hobby matting I have hanging in my refugium for algae to grow on so I can harvest it like a scrubber.

Be aware that there is a whole group of people who run algae scrubbers to a disciplined formula and do not do water changes. So, something about that has a value worth consideration. This is why I have adapted some of the concept to my refugium. If would be nice to do away with water changes but that is not necessarily my personal goal. I want the safety advantages that a concept which has proven to do away with water changes can bring to my eco system as a safety margin. My thinking is if I use a fair amount of that concept AND do water changes I have taken advantage of both disciplines. To make this concept work for you, you must FEED the tank, and that takes a steady tiny incremental daily increase of feed volume over a few weeks to pull off.

mayday610 · Feb 13, 2013

Water flow through your macro is your friend. Are you going to get more bugs in your teeth walking down the road or cruising on your bike? And as far as how much.... its crazy to say that you need tons or none at all... Any that you put in there is helping. Put in whatever amount works for you. It will grow and you will eventually have to prune it back anyways.
Also in agreeance with the rubble. Any aditional surface area for bacteria is always a good thing especially when the stock in the tank increases.

nickbuol · Feb 14, 2013

OK. Cool.

For the macro algae, how long should the light be on for it? I was thinking about tying the timer for that light in with my "moon lights" timer that kicks in overnight. Should (in theory) help keep the pH more stable overnight and still give the macro pleanty of growing time. Thoughts?