[Old Board Archive] Live rock comments, etc...


Staff member
May 30, 2000
Live rock comments, maintenance questions, and whatever else I can think of!|rrtanton
Okay! :) With the assistance of Tonmo's excellent members, I've completed the design and setup of my aquarium. System has been running for about two weeks now, the last week with live rock. Now I have a new collection of comments and questions, geared more toward some technical and maintenance issues. FYI, here are some more details of my setup if needed:

--55 gallon 4' X 1' glass tank
--Eheim Pro II filter (the smaller model...forgot the number!)
--CPR Bak-Pak protein skimmer w/preskimmer
--2 fairly hefty powerheads on either end of tank (one is a rotating powersweep)
--60 pounds aragonite (20 of which was live sand, retail bagged store-shelf variety)
--About 55 pounds of Harbor Aquatics live rock
--220 Watts PC light (half daylight, half actinic.)

First, comments on the live rock. I am not especially qualified to review it critically, but the Harbor Aquatics Fiji rock I purchased seems very good. Various shapes, with lots of pores and holes, and it seemed healthy and well-cured with no bad odor. There is plentiful coralline algae in deep purples and some reds, a large amount of small macrophytic (plantlike) algae, there are oodles of featherduster worms (and a few free-crawlers...not sure what these guys are but might be amphinomids...:neutral:), a few small shrimp/copepods (also unsure of desirability), a few small sponges, a few small stony coral polyps (have no idea how to diagnose their condition yet!) and what I'm pretty sure is a very tiny chiton.

The owner runs the operation out of two sizeable greenhouses in her backyard. She was friendly and accessible, answered dumb questions, etc. We picked out rock together, trying to find both unusual shapes and appropriate sizes for my tank's dimensions. The location in Valparaiso, Indiana is (for me) convenient as I pass near the area regularly (Chicago is about an hour away) and it enabled me to both avoid shipping costs and get the rock home the same day. She apparently does a substantial amount of business, and offers other inverts and fish alongside live rock. She will ship overnight, but pretty much refuses to ship if it can’t reach you fast enough.

Now, on to some questions.

Both my powerheads are using their venturis and the skimmer naturally bubbles like crazy. The surface water is agitating very nicely. So I think I have enough O2 in there...but I also have a lot of bubbles from those powerheads. My rock has a ton of bubbles stuck to it, collecting in pockets, etc. I guess it doesn't bother me much, but is there any potential problem with so much bubbliness?

My lighting is as mentioned above. I'm told octos don't like intense light much. Is this purely "He'll hide when the lights are on" or is it "He'll stress out and be unhealthy?" I can remove tubes to scale back the wattage, but if I decided later I want to add some light-loving cnidarians, would the octo essentially preclude me from doing so? The rock does have plenty of dark hiding places. Also, would the octo prefer a specific lighting-cycle?

I read an article suggesting that standard hydrometers are consistent but not very accurate (that they need calibration.) I took my Seatest swing-arm into my LFS and compared it to their Deep Sea model on a sample...theirs read 1.021, mine read 1.026...consistently, with several trials and different people to rule out user error. Any advice on calibrating these things? They didn't have an optical refractometer and those sure are pricey... I'm a bit concerned about whether my salinity is actually what this hydrometer says.

The tank has been running with live rock and sand for a week. It seems remarkably clean...the skimmer has skimmed nearly nothing, the chemistry comes back essentially zero on ammonia, nitrite, nitrates, pH & Calcium high... I know the thing can't be properly established yet...should I expect to still see these values shift with a bit more time, or with essentially no load will it do so subtle a cycle I can't see it? Does it actually need some load to cycle? If so, what would be safe to add? I don't wanna add anything too soon...

I kinda wouldn't mind keeping the tiny critters on the live rock alive (feather worms, sponges, etc.) Do I need to feed those? Would the leavings of a larger critter added to the tank be enough?

Thanks for your advice...I hope my live rock information is helpful to someone.


Re: Live rock comments, maintenance questions, and whatever else I can think of!|octomonkey|

glad to see that it is all coming along nicely!


bubble--- well I never use the venturis on a powerhead for that very reason. I think itcan look pretty for about five mins but then it becomes a pain. The bubbles stick to everything. I have seen them in people's tanks sticking to corals and fish too. You dont really want them majking pockest of air on your live rock, it is disadvantageous to the animals and plants trying to grow there. Simply run the powerheads close to the surface so they are moving the surface layer. That should be enough.

The lights---- all depends on which species of octopus you get. Some are nocturnal and some are diurnal. An Octopus bimaculoides is the most commonly available diurnal octopus but it is not suited for a tropical tank and O. cyanea is also diurnal but too big for your tank! And it depends on the individual too. I think you will just have to wait and see what your octopus is and what it is like and try changing the lights then.

As for Cnidarians... some of them are going to need very bright lights so you will need to choose carefully. The biggest problem I had with keepingthem with cephalopods was simply the mess that they make. Most modern reef tanks are almost sterile with no nutrients. That is very hard to achieve with an octopus in there messing it up!

I bought a new hydrometer about 2 weeks ago. Before I bought it I asked the shop owner to test it for me agaisnt one of his electrical salinity meters. It was 1/2 degree up. I can live with that. My last one was 2 degrees down. So, if you can get it tested before you buy it (and you are well within your rights to buy something that is tested and works!) all the better.
The swing arm hydrometers cant be calibrated by us. The one type of hydrometer that never fails is the glass one that float. Look a bit like a thermometer. That may be a better idea for you.

The skimmer can sometimes have a break in period of a week before it works, but i dont think that your tank is producing anything for it to skim out. Sounds like your LR was already cured. So, as long as its set up right, it will produce gunk when the gunk is produced in the tank.... once you get your stock for cycling. perhaps just stick in 6 black mollies after lettingthem get used to salt water after an hour or so.

The stuff on the LV will normally do fine by itself. Especially the feather dusters that can catch all th bits of detritus blown about by a hunting or eating ceph!

Hope that helped

Re: Live rock comments, maintenance questions, and whatever else I can think of!|rrtanton|
Thanks Colin, advice much appreciated as usual! Honestly, I'm the sort that likes to "do it right" at least within vaguely reasonable budgetary paramaters, so I admit I'm vaguely interested in an optical refractometer, but the price is awfully prohibitive. There's a glass floating hydrometer from Hagen, I think, that was suggested as highly accurate, and only about $20, so I'll look into that.

Disconnecting the venturis on the powerheads seems to have had the desired effect, bubbles are diminishing. The skimmer seems to be behaving more as I'd expected now...last few days its been filling more, so I'm more comfortable that in a while I can fine-tune it.

I certainly intend to acquire a bimac, though I understand the uncertainties involved! There do seem to be at least a couple suppliers that have a good reputation of providing what you ask for. I'll see what comes in, and adjust things accordingly.

Thanks a lot for the help...if anyone else has comments, I'd be happy to hear them. By the way...one of the websites I've looked at recently was liveaquaria.com, part of the Drs. Foster & Smith outfit. They list bimacs and identify them as aquacultured...I gather that's a more preferred way of acquiring an octo? Even more intriguing, they list cuttlefish, identified as "Metasepia sp." from Indonesia. If the image they offer is accurate, I've never seen their cuttle before...startling highlights of red, pink and yellow. These don't appear to be cultured, and the price is steep. Also, they aren't currently available. Anyway, just curious as to what anyone might know about them...a source of cuttles in the US, as I'm learning from the board, would be a much-appreciated thing. Not for me though (yet...) I want an octopus! :)

Re: Live rock comments, maintenance questions, and whatever else I can think of!|octomonkey|
Well Metasepia is a species that I would consider in the same terms as the Mimic Octopus and Wunderpus. They should not be imported. Cuttlefish have a bad enough time as it is and on top of that, imported Metasepia can go for $200 and are fully grown when offered for sale! Max size is 8cm and a real waste of money for a few weeks of having a cuttlefish at the end of its lifespan. They do look really cool though but worth avoiding until someone starts producing juveniles under aquacultured conditions...

Glad the bubbles have gone... :)

Re: Live rock comments, maintenance questions, and whatever else I can think of!|steve o'shea|
Here's an interesting how-to-do link for anyone considering propagating gorgonian corals in an octo tank. Could look smashing!


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