• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Miss anything?

Kharn

O. vulgaris
Registered
Joined
Jun 16, 2008
Messages
83
Hello all

After much more reading I still cannot get over the terms "The solution to pollution is Dillution" and "Get the largest Tank within your budget" so I decided to up the size of the tank. I have made a list of what I need to get with approximate sizes and volumes.

Tank - 72x36x30 (inch) = 300Gals
Sump - 18x24x30 (inch) = 20 Gals (filled to operation level)
Refugium - 36x28x30 (inch) = 127 Gals
Skimmer - Octopus Hurricane x2500 (rec for 2500L, out sump)
Overflow - Internal at either end of the display tank.
Live Rock - Estimated 670Lbs.
Sand - Not sure yet, (1 inch off bottom)

There will be minor lighting on the display tank (a single 10W Fluro and twin strong Fluro's for the Refugium), also a heater (if necessary) and test kits to record Ammonia, Nitrite, Nitrate, Phosphate, Calcium, PH and Copper.
The sump will be like most other sumps

The RO/DI water is probably the only thing that is really giving me concern at the moment, however my LFS (which happens to be the biggest and best in the southern part of QLD :cool2:) has a constant supply of "seawater" ready to sell by the barrel and they are less then a 40min drive from my place.

So with all the above I believe I am ready to house a Ceph? Did I miss something? Is there a crucial error that you can see and I cannot? Would a Octo be happy in the enviroment im trying to provide?

Thank you :biggrin2:
 
Can't you buy a RO/DI filter to hook onto your faucet? Then you would have an endless (albeit slow) supply whenever you need it...

That is a big tank, wish I had room for one that size... oh well, next renovation project :biggrin2:.
 
Yes, I think you are missing an important concern. You will need to top off that tank on a regular basis with FRESH water, the seawater is only good for filling and water changes. Automating the process in your sump would be a blessing but will require an RO/DI unit and some engineering (the amount of creativity depends on where you have a water supply and drain). I would also consider up-sizing your sump as a 20 gallons container is very small to hold the equipment you need for that kind of water volume. I also hope you have taken into conseration the weight of 300 gallons of water as that is likely to need to rest on a cement pad or require additional floor bracing. I am not at all well versed in the needs for this sized tank but one of our members mentioned a forum that specializes in high gallon tanks and you might pop over there and get some opinions:

Building My 50,000 Gallon Monster Mega Tank
 
1/ Firstly the weight could be anything, it is indeed on a concrete floor.

2/ My tank is going to be in a "sunlight FREE" zone meaning there would be no outside light coming into the room where the tank is being housed. (I am hoping this limits the amount of evaporation and un-wanted algae growths etc)

3/ So the RO/DI Unit is more then I thought, well I have a solution to that as well it may be strange and I don't know if it will work. I do have two Rain-Water tanks (7,500 Litres all up) rite outside the room where the tank is going to be, could I connect an RO/DI unit to them and use my Rain-water tanks as auto-top offs?

As for the sump that was an estimate, I figured the sumps dimensions by gathering what was left over in space (since I wanted both the sump and Refugium to be in the Display tanks cabinet) the Refugium will take 1/2 of the available space in the cabinet while the other 1/2 is left for the sump and External Protein skimmer. I think I neglected too mention that the sump will have a Bio ball setup in it with a Filtration mat ontop, the water from the refugium will flow onto this mat through the bio balls and into the sump.

EDIT: "I do have two Rain-Water tanks (7,500 Litres all up) rite outside the room where the tank is going to be, could I connect an RO/DI unit to them and use my Rain-water tanks as auto-top offs? "

THIS WILL NOT WORK for me, I just called that pet store to see if it could somehow work and if they could help install it. They believe there will be a pressure problem where there wouldn't be enough pressure made to push the water through the membranes of the RO/DI Unit.

Sooo i must get a fully installed one (i'm going to go all out on this RO/DI Unit) I got a nice deal from the pet store, they hooked me up with a bloke that is very experienced with installing RO/DI Units specifcally for Aquariums.
 
What kind of octopus are you planning to house? 300 gallons is pretty extreme for an octopus tank. There are only a couple of species that make it into the trade that would be noticeable in that size tank. I would also recommend the sump be bigger. The dimensions of your refugium seem to be a little extreme for under the tank. Making that smaller will allow room for a larger sump. Bioballs are a waste of time. Live rock will do a much better job. Use live rock rubble in place of bioballs if you really want to use them, but with the amount you are planning on having you will not have any problem with having enough surface area for the biological bacteria to reproduce. I would use T5HO lights for your refugium instead of standard fluorescents. The refugium will be more effective when it is shallower and has more surface area.

Is there a reason for an external protein skimmer? In sump ones almost always work a lot better, and cause less of a mess when the collection cup overflows.

Ten watts is extremely dim. On a 6 foot tank I don't see how 10 watts will make any kind of difference besides directly below the bulb for maybe a foot or foot and a half deep. Any ambient light will drown out a 10 watt fluorescent bulb any day. I recommend you get 2-36" fluorescent fixtures or 1-72" fixture so you have equal lighting throughout the tank.

A 300 gallon tank is going to be pretty packed with almost 700 lbs of live rock (assuming the majority of the 670 lbs will be in the display). 300-400 would be a more logical estimate for a nice look that isn't cluttered. That is still a lot of rock and you will be able to make plenty of potential dens and overhangs easily.

You will want 2 internal overflows and not just 1. There is a lot of water to move around in that big of a tank and you won't be able to get much circulation with only 1.

Some questions -

Have you considered return pumps and water circulation methods?

Do you have a good idea about what you are going to do to secure the top of the aquarium as well as overflow boxes?

What kind of plants are you going to grow in the refugium (after all 127 gallons is pretty huge)?
 
If you are going to use your rain water you may need a pump if you do not have a minimum of 60 psi (higher is better but 60 is about as low as you can go and get water to pass through the RO membrane). Secondly, the RO unit will need a drain (at 60 psi you will get about 1 gallon usable for every 4-6 gallons you process, a higher psi will produce less waste). Depending on your use of the rainwater cistern, you could plumb the drain back into the tank to keep from making a mess and needing a drain. Do note that the run off water is called "Brine". It has been filtered by the unit's particulate and carbon filtration but it is the water that is rejected from the RO unit so it will have a higher mineral content.

Recheck you measurements on your cabinet if you are planning on putting the skimmer in it. Your skimmer will not sit on the bottom (it will be elevated) and you will need overhead room to lift and remove the skimmer collection cup for cleaning. Depending upon your skimmer, this can be as much as 6" in addition to the elevation from the bottom. I am concerned that you may be overcrowding your cabinet (been there, done that) and that you might want to consider using a a much smaller refugium (I am assuming now that it is not for display) and allowing more room for your sump.
 
Hello

The octopus I plan on keeping is yet undefined, I am trying to create an enviroment capable of housing Octopus (any home aquarium size, that being said a Vulgaris would be nice) and Cuttlefish, however only one will be housed at any given time. The Refugium is as big as it is because within the cabinet there will be a sort of centre brace dividing the tank's cabinets into halves, one half is the Refugium the other half is the Sump and Protein Skimmer.

I can take the Bio-Ball section of the sump out all together if its not needed, as for the lighting I never really was that intellectual on the tanks lighting soooo, Thank you. You say "The refugium will be more effective when it is shallower and has more surface area." I am not sure I fully understand why, please explain? I mean it's not a problem to have the PvC pipes re-drilled but isn't that just going to lower the Volume in the Refugium?

As for the Skimmer the one I noted was the larger of the two I was looking into, the other is an In-sump skimmer 'Octopus Core + Pentair 1500i' recommended for 1,500L. If that skimmer could handle this volume of water then I'd use it, I read in a few differen't posts that you should go with your budget, the Hurricane x2500 is said to be able to handle 1000litres more then the Core + Pentair and I can afford it. As for the Live Rock I worked off the general theory of the tanks volume (in gallons) to pounds of Live Rock, for each gallon of water I added 1 1/2Lbs of Live Rock (guess that was over kill?) Umm as for the overflows I thought I said there were two internal overflows one at either end of the tank?

As for the circulation of the whole system, which I did leave out, there will be a large pump (undefined size yet) in the sump which will be sending the water back to the display tank, there may also be (if needed) powerheads within the display tank to keep a constant current going. I have had some ideas about sealing the aquarium top but that is where the actual designer comes in, this is a custom built fish tank, this fish tank is built for Octopus and cuttlefish and with that note it will be built to a sort of "Arcatraz" style no gaps, all sealed and either clamped down or locked down.

The overflow boxes will be designed in a similar manner with a 'meshing' over the top secured down firmly so the octopus can't get in to the overflow or pull the 'safety mesh' off, I will be bluntly honest, I have little knowledge into sorting out what plants I need for my Refugium, However I'll know doubt find it within the text of someone previously in these forums.

I miss anything else or something that NEEDS to be clear? Before I accidently kill my Octopus...

Thanks in Advance
 
Cement Issues

I've done a lot of work in cement over the years. And I've gotta say, you should have your area checked out. I can't tell you how many times I've been called to peoples houses with foundation problems :banghead:. It's hardcore expensive and a pain in the ass for owners. You want to make sure that your cement is decently thick, in some states it's done differently then where I live in california (less concern for earthquakes in other states). I've never personally seen it done, but there are companies out there with a sort of xray machine that can see into your foundation and look for cracks, density problems, and of course how deep the cement is. Houses built by some companies, such as Hoffmann Homes, are very prone to foundation problems as well. What tends to happen is when land is getting developed, companies are supposed to level an area and let it sit for a year or more. This makes all the dirt settle with some assistance from rain and whatnot. When they put cement on land that they haven't done this on, the weight of a house can press part of the area down where the dirt isn't solid underneath, resulting in a whole lot of split cement. If your house is 10+ years old, that shouldn't be a concern. I know I'm rambling, but somethin like that can be a huge expense. Good luck with your project, it sounds like it'll turn out pretty bad ass.

-Keith
 
I figured through scratchy calculations that it will be better for me to just install an RO/DI Unit just outside the room where the tap is, there is also a drain directly under this tap, I was more worried about this RO/DI Unti costing me over $1000 :hmm: to fully install
 
Hello

For the cement issue Keith I do believe that it will not be a problem, you see this aquarium is setup in the Den of our house, down stairs on the actual ground. So there is a cement slab (which the house itself sits on) followed by earth.

Cheers
 
Be sure you find the floor to cup removal (not cup height and not total height but elevated height + physical height + removal height) clearance needed for the skimmer. I fear you underestimate the physical size of the unit. Also I doubt a single center brace will be sufficient to support the center load of over a ton (MORE than 2500 pounds/1125 kg) of water, rock and aquarium. It might be best to talk with your tank/stand manufacturer before you order anything for under the cabinet. You may want/need to consider building a side (or matching side) cabinet(s) to house the skimmer. We were considering something on this order ourselves before going with a corner unit but it would have given us a good place for conveniently hiding supplies as well as a consideration for above tank display refugiums.
 

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