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Blue Ring
Dec 13, 2002
Thank you very much for your advice.
The final plan for my tank seems to be shaping up, but I have a few l last major questions.

1) Although I asked in a few of my last posts about my filtration, I have encountered some difficulty in deciding on the best equipment. Several choices are available and I would appreciate any advice that would make this decision any easier. As mentioned earlier, I plan to keep a 40-gallon tank with live sand, but NOT live rock (cost).
The first option in a H.O.T (hang-on-tank) Magnum Pro System ($54.99). It contains a hang-on-tank canister filter AND Bio-Wheel Pro 30 spray bar for biological filtration. It is rated for 250 gph.
The second choice is similar to the first, but is the Magnum 350 Pro System. It has a regular stand up canister filter AND a Bio-Wheel Pro 60 (two Bio-Wheel 30s) for biological filtration. It is rated for 350 gph.
After reading other posts on this site, I have considered a more expensive third choice. For mechanical/chemical filtration I have considered a Fluval MSF 104 Filter for 125 gph. Since I have read that canister filters are poor choices for biological filtration, a separate supplementary biological filter seemed necessary. For biological filtration, since I'm not using live rock, a Fluidized Bed Filter (up to 300 gallons) ($53.99) was a possibility.
The third choice is the most expensive and the least favorable. Since I'm not using live rock, but I am using aragonite sand, should I use a supplementary biological filtration? If so, can a spray be used?
(NOTE: all of these filters can be found on doctorsfostersmith.com)

2) What brand and sort of air pumps would be good choices to provide oxygenation?

3) Since bimaculoides was mentioned to be a good species for a 40 gallon tank, will supplementary chilling/heating be necessary? Being in Chicago, IL, the temperature varies: 20s in the winter and 90s in the summer.

4) After looking in a fish catalog, a cheap tap water filter ($29.99) seemed appealing. However, it only uses carbon and ion-exchange resin. Can a tap water filter of this type be used, or will I have to invest in an expensive RO unit?

I thank anyone who has offered advice in the past, and anybody who will. Without this message-board, the raising of the octopus would be difficult, if not impossible for me.
Hi Again! :smile:

Living in the Uk i dont always have access to the same filters you mentioned apart from the Fluval range which are my personal favourites anyway, so if anyone wants to jump in and discuss the Magnum filters, please do :smile:

From reading your posts, the fluidised sand beds have the largest surface area for bacterial colonisations out of all the filters so get one of them if you can. I have one running my 140gal FW tank. I really do recommend them. But i would therefore use something like a Fluval 4 in the tank just for actually catching dirt and keeping stuff clean! http://shop.store.yahoo.com/worldpets/fluvunfil4pl.html That was just the first site i came across with a pic :smile:

Spray bar is an excellent idea as it increases aeration, position it just at the water level for maximum effect.

Over the years i can guarantee that the quietest/best airpumps are the Rena range! I have a 400 in my livingroom which is virtually silent, unlike many other brands.

A tap water filter can only be a good thing. The more we do to provide a healthy environment the better.

I am sure that you will need a heater in chicago for the cooler times of the year. And carefull placing of the tank may help you get away with no needing a chiller. In scotland its much easier as its always cold! I dont need to worry about getting a chiller for a bimac LOLOL :lol:

Hi B25:
There is one important piece of equipment that you did not mention above. I would highly recommend a protein skimmer particularly if you are not going to use any live rock.

You may also want to consider a wet/dry trickle filter. It would allow you to keep the heater and other peripherals out of the tank where the octo can get to them. I've recently discovered that this makes Octo-proofing the tank a lot easier. I have seen wet/dry filters on ebay which include pumps, overflow boxes, all plumbing and bio-balls (some even have a built in skimmer) for not much more than a fluval 401 will cost you.

I've included a picture of my wet/dry filter - protein skimming set up (its mostly homemade though). Hope that this helps.
My $0.02 worth:

Live Rock--I'm somewhat new to all this myself, but setting up my first tank (a 55gal) went very smoothly, and it's run wonderfully clean ever since. I suspect a big part of this is my live rock--the fact that I have it, and that it's very high quality. I think it's really stabilizing my tank (bacteria in there do some good biofiltration), plus it offers a lovely, diverse little ecosystem to watch.) You live in Chicago, you mentioned...that’s perfect. The supplier I used is HarborAquatics.com, located in Valparaiso. Their rock is genuinely fully cured, covered with lots of wonderful critters, and only $4 per pound. You can add 40lbs to that tank for $160, or much less if you want to save money. Best of all, since you can drive out there yourself to get it, as I did, you don’t pay shipping and your rock won’t have any “die off” along the way. Please, someone tell me if I’m overestimating what the live rock does for my tank or the quality of HA’s rock, I am a “newbie” after all... :smile: ...but since the very short cycle period after startup, I’ve never once had detectable levels of any nitrogenous compounds, even nitrates (I think the leafy algae on and the bacteria deep in the rock gobble my nitrates up.) I thank my rock, plus taking things very slowly.

Biofiltration--Again, I blame my live rock for this...but I have little special biofiltration. Besides the Eheim canister and live rock, all I have is a CPR BakPak skimmer, which offers some extra “insurance” biofiltration in the bio-bale chamber. If you’re looking to buy a Magnum canister bundle, it comes with bio-wheels which are (I’m told) excellent wet-dry biofiltration.

Skimmer–I would agree, all I’ve ever heard of octo tanks and other sensitive-critter tanks is that a skimmer is a must. Plus, it provides aeration for the water...you may not need a separate airpump or stones.

Canister filters--I have read good reviews of the Magnum series, for effectiveness and reliability. Given their price, if you're on a budget they're probably the way to go. I'm told you can never have enough filter, so if you can manage it, perhaps the 350 is the better choice. I went with an Eheim 2026 (from the Pro II series) because I like fancy European things. :P It is supposedly nicer, and I do love it, but for the price I’ll bet the Magnum is the true winner. Best price I've found for Eheim is on dr.fosterssmith.com, and they include the expensive media. If you want wet-dry filtration in one package, Eheim makes a version with a neato integrated wet-dry filter...but it does cost a lot more. Their Magnum prices are competitive, but not the cheapest...I think even the big chain bricks-and-mortar stores can sometimes be cheap for Magnums?

Water prefiltration–I wanted good tap filtration but just didn’t want to spend $2-300 for a ro/di filter. My solution might be risky, I don’t know...would also welcome comments on this...I found advice from good sources suggesting this should work, and so far I’ve had no problems, but I really can’t swear it’s adequate or not. I built a filter out of PVC pipe and Poly-Bio-Marine’s polyfilter media. Many people swear by this stuff. I hooked up a Pur faucet-mounted carbon filter to my faucet, and I run water from that into my crude filter and then into a bucket. It’s a bit awkward, but it is very cheap and surely is better than tapwater, and you can “recharge” the media. I can try to find the do-it-yourself guide I used, if you're interested...I think I found it on saltaquarium.about.com.

Hi rrtan:

The polyfilter filter idea is an interesting one. They do adsorb copper and other nasty substances which seem to be a major danger with octos. However, depending upon your water supply, you may run into a problem with silicates and phosphates. If you experience algea blooms this may be the reason.

I cannot overestimate the value of live rock. Aerobic bacteria on the surface convert ammonia to nitrite (Nitrosomonas, Nitrosococcus etc.) and then other aerobic bacteria convert the nitrite to nitrate (Nitrobacter, Nitrocystis etc.).

Most biological filtration systems end the nitrification cycle there (necessitating those frequent water changes as nitrate levels rise beyond acceptable levels). However, the pores of live rock are a perfect home for anaerobic bacteria (Denitrobacillus, Micrococcus etc.). The nitrates are transported to these bacteria within the pores of the rock which then convert the nitrates to nitrogen and oxygen gas which can then disperse from the water. Thus, live rock does for your marine system what most filtration sytems cannot. (I'm not a big fan of coil dinitrators). In fact, many reef keepers remove the biological media from their filters because they tend to short circuit the nitrification cycle. They rely instead upon live rock and skimming only.

I have kept marine tanks with and without live rock and have always found that those with live rock seem to be more healthy and certainly more stable.

My advice if you are on a limited budget is to possibly build some of the required items yourself. (Check out this page for some ideas How to Care for Saltwater Fish
You also might want to consider a live rock setup with only a good skimmer and run the skimmer output through additional carbon.

As for Fluval canister filters, I have used several over the past couple of years. I have found them to be very good at mechanical, and to a lesser degree biological, filtration. However, I have noticed that the spindle which the impeller spins upon is made out of plastic. It will break off with very little force so you have to be careful when cleaning them.

YOIKS!!! :roll: But I digress. I hope that this little diatribe has been of some help.
Another question came to me as I read this...Colin, you mention fluidized bed filters, and I've read elsewhere that these things are just phenomenal biofiltration systems, which makes sense when I remember my aquatic biology classes and the workings of sewage treatment plants. :smile: I've read, however, that there's a problem with these things not tolerating nearly any downtime...that they "crash" within minutes of being shut down. Have you observed/heard of that? Is it a problem that can be mitigated somehow?

Glad to hear another opinion on live rock. Does anyone else have experience with HA's live rock? For anyone within a remotely reasonable range of Chicagoland, they seem to me the best option available, in price and quality...but I'd love to hear another opinion.

Hi rusty
my fluidised bed is actually on my 140gal freshwater tank. Some of the species in there are really sensitive like wild angels and a FW stingray. When i set up the tank it was actually an after thought as it had been redundant in my cupboard for a while but is now actually the main form of filtration, the other is just a small Fluval for catching dirt.

Anyway, i can see that a fluidised bed with so much bacteria would become anerobic quickly. So it would make sense that it could crash easier. I often leave it off for an hour at a time with no affect at all on the tank as far as test results show. Ammonia and nitrite always zero and nitrate highest record was 12.5 which is nothing for a FW tank!

I have read that even with other filters like Eheims they shouldnt be off for more than an hour either. Interesting topic though. anyone else got ideas or suggestions?


PS i dont think that a fluidised bed is too difficult to make either!

Thank you very much for your responses everyone
As I am on a tight budget, and I have recently read a post stating that live rock would be better than having a biological filter (my original plan was to just have a Magnum 350 without live rock). Is this true? Also, high intensity lighting required for live rock to be effective? If so what kind and cost?
I realize that I am asking probably unnecessary questions, but due to my tight budget, I would like to do everything cheaply and correctly.
Also, would a protein skimmer provide the necessary oxygenation, or would supplementary airstones be required?
Thank all of you for your time and effort.
B25, you can never have too much information, so don't feel bad. Also, that justifies my verbose postings! :oops: :P When setting up, I researched...and researched...and researched...I probably put myself through the equivalent of a one-semester college course! And I STILL don't know THAT much... :P

Yes, as posted above, I think live rock is that great. You can easily make a tank without it, but it'll require extra equipment to do the biofiltration the rock would have done, and it won't look as nice nor have nearly so many interesting critters inside. A tank with just water and sand isn't as interesting as a tank with different-shaped rocks, looking like a reef, with pretty purple and red encrustations of coralline algae, leafy plant growth, little featherduster worms, etc. And your octo will love you for it...it offers tons of wonderful places to hide, just a great habitat for him.

As I think about it, whatever biofiltration you buy to do the work live rock would do will also cost some money...less, but maybe not that much less. So yes, I would very highly recommend buying some. As I mentioned, you're lucky to be living in Chicagoland, since Harbor Aquatics in Valparaiso is a reasonable trip for you. You can handpick your rock (nice), you avoid the rock dying partially during shipping, and you avoid the insane shipping fees for live rock (in your case, those fees would cost more than the rock itself!) Rule of thumb is one pound per gallon, so 40 pounds at $4 a pound of their high-quality Fiji rock would be $160, and you can probably do 30 pounds or even 20, depending on what you really think you can afford. For pretty rock plus animals and biofiltration, $100-$160 or so is kind of a bargain.

For a 40 gal tank, maybe you could get away with one of those Red Sea Prism skimmers? They're very cheap online ($60, I think?), compact, and supposedly work okay for a 40 gal tank. I'm told it's not the best but that they work, and high quality skimmers cost a lot.

My 55 gal has not shown any signs of needing extra oxygenation. Oxygen is difficult to measure, however...I'm not aware of any cheap testing kit/method for it...is anyone? Good circulation and some fairly gentle turbulence near the surface helps a lot, which is why you should have one or two powerheads in the tank stirring up water, mounted close to the surface.

My understanding is that high-intensity lighting does very little for live rock beyond encouraging algae to grow, which must be plucked off regularly. Stony corals DO require intense light, but live rock is not actual lumps of living coral...it's either coral that's been dead for a long time, or volcanic rock. It may have little corals living in a few places on it, but whether you want to keep those alive is entirely optional.

I do have very bright lights in my tank, because I wanted to have some of the prettier stony and fleshy corals. If you want to have pretty living corals in your tank (and some are just gorgeous) then you will need some quality (and expensive) lighting. And you can't really cheat on this...everybody told me that, and I tried anyway, and all I did was waste money. If all you want is an octo, then you can go cheap on lighting, they prefer less light anyway. If not, may I recommend this site: ahsupply.com. This is Aquarium Hobby Supply. They offer very good Power-Compact Fluorescent lighting kits with electronic ballasts for aquaria at cheap prices (for this kind of lighting.) If your tank is about 3 feet wide, you could probably use one of their 96-watt kits which, with combo-bulb, would cost about $100, a bargain for quality, intense, energy-efficient light.

Hope this helps!


I thank everone for their advice...
Although rrtanton did say that live rock did ct as a good biological filter as well as being aesthetically pleasing, due to my circumstances I am afraid live rock is out of the question. This is becuase I need the entire tank space, because I plan to perform scientific experiments for the science fair on consciousness and behavior. In addition, the cost is high (even though in Valpraiso the prices are cheap) and lighting would add to this cost.
Therefore, I wish to ask whether I could use the Magnum Pro 350 with a Seaclome skimmer and still manage to keep a healthy and stable tank without live rock.
Thank you,
Michael O'Shea[/i]
Hi Michael:

As much as I love live rock, if you can't afford it then you can't afford it. I will note that you DO NOT want to leave the tank completely open. Your octo will need plenty of hiding spaces to feel secure and be healthy.

As for the Magnum seaclone combo. I have kept healthy marine tanks with worse equipment, but keep in mind that you must keep a close eye on your water parameters. Particulary because the seaclone skimmers, while inexpensive, are not that great. (I know because I have several!!) As an alternative to the seaclone you may want to check out http://www.fishsupply.com/cgi-bin/f2/common/store.cgi?dbname=f2&path=top/X/XS They have WON Brothers skimmers which are quite inexpensive as well. (can be used in -sump or hang on) you will need to purchase a water pump for these skimmers but even with the additional cost the total will not be much more than a seaclone, probably about $85.00. The Won Brothers Clean Up 75 is $59.95 and you can get a Surge 3500 water pump for $24.99 at big al's online The Won Brothers skimmers are not as good as the much higher priced skimmers but I've found that they do an excellent job. (Pulling out far more gunk from the water than the seaclones do. Hope that this helps. Here is a pic of the above-mentioned skimmer in action.
Ah...I understand better now. And you certainly don't NEED live rock. One possibility is a sump, as mentioned above. 'Tis my understanding some people use live rock in sumps. And just in case I confused you, live rock doesn't need light...it sounds like your tank won't need anything but very basic light. But that's somewhat less reason to want live rock anyway, since part of having it (I think) is seeing it.

Didn't I see somewhere that someone's selling sumps with integrated skimmers and wet-dry filters?


Thank you for all of your responses
However, rrthanton I don not have the money to buy a sump…therefore I will attempt to get by with a Magnum 350, Aragmax Sand, a Seaclone skimmer (or a different, better one), and cheap lighting. Thank all of you for your responses.
Michael O’Shea

you could use lengths of plastic piping (food grade quality) to increase the hiding areas rather than rocks..... a lot easier to move and cheaper too :smile:


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