Starting 5x2x2! Need help with tank design

[mozesyap]

Hi all,

I am planning on a 5x2x2 planted. But I am still struggling with the basic tank design:

1) Whether to get a sump or to use canister filter. I can't find any thread which consolidate the pros and cons of each method. I am starting to lean towards sump because of easy maintenance.

2)Is 5x2x2 too big for a 5room HDB flat? Should I downgrade to a 4x2x2?

3)I am planning to use MH, so I probably need a chiller. Is a chiller going to be a bad idea in the living room? How do you ventilate the chiller?

4) How do you diffuse CO2 for such a big tank?

5) Would a budget of 6k be enough? (if i want high quality stuff for everything)

Hope I can get your expert opinions

[deacon]

I am planning on a 5x2x2 planted. But I am still struggling with the basic tank design:

Maybe can research alot more on plants and what type you wanna get. Take a few trips to some LFS like Seaview Aquarium, look at the plants and driftwoods to help you visualize your tank. Write down a list of the flora you'll aim to get.

1) Whether to get a sump or to use canister filter. I can't find any thread which consolidate the pros and cons of each method. I am starting to lean towards sump because of easy maintenance.

Sump is definitely a true tried and tested way. But you must know how to do it right, else in the event of a power failure, you'll have 5x2x2 worth of water on your floor.

2)Is 5x2x2 too big for a 5room HDB flat? Should I downgrade to a 4x2x2?

Anything above 600KG will require a permit from HDB. Your 5x2x2 dream, just water alone, is about 568 litres = 568 KG. This is excluding all the substrate, equipments and a sump if you choose too. Some folks don't get permits and just go ahead and do, but guess who is going to pay for repairs if your neighbor's ceiling below starts cracking.

3)I am planning to use MH, so I probably need a chiller. Is a chiller going to be a bad idea in the living room? How do you ventilate the chiller?

Yes, with MH you'll need a chiller.

4) How do you diffuse CO2 for such a big tank?

You can use an inline diffuser (external reactor) for this. The CO2 is mixed along with your output flow. Good news is, this can be fairly easy to DIY.

5) Would a budget of 6k be enough? (if i want high quality stuff for everything)

Sure, if you stay away from overpriced ADA products, there's lots of other great decent brands out there.

[shrimppaste]

Sump is good but one thing to take note, it will result in a lot of CO2 loss. So you may need to pump a lot more Co2. 2 Cannisters maybe a good way to go. You can wash one while the other is running, vice versa.

[Desewer]

hmm... if your sump is based on an underflow system, in the event of a power failure yes you might get 5x2x2 worth of water on your floor.

but if your sump is overflow-based, i fail to see how the water can flood your floor if there is a power failure and your return pump doesn't work?

[mozesyap]

Thanks for your reply guys.
One thing that keeps me worrying about sump is the amount of noise it would make. Can anyone who is currently using sump give some opinion? Is it pretty noisy?

[elmo]

sump would be a better option should you decide to get fishes with higher bioloads in future.

[bossteck]

Well constructed sump filteration will never result in any flooding in the event of pump failure regardless of whether overflow or underflow is used. You can have underflow flowing into a compartment and the water there going into the sump via a standpipe (end of the day, it is still overflow system)

One simple trick I would recommend is to switch off the pump while you're filling up the tank / sump. That way, you know for sure the total volume will be accomodated by the tank + sump.

[BT Lee]

Dear Mozesyap,

Note : I have edited the earlier post as it has flaws.

I hope you have not ordered the tank yet.
If so, I would like to share with you some important aspect of overflow arrangement that will be useful.

If possible try to have 3 holes predrilled at the bottom of the tank at a corner most not exposed to view.
These holes should be as near as possible yet allow for installation of the bulkhead and pvc connector.

Overflow can be easily achieved via one simple overflow pipe but from my humble experience, that may not be an ideal arrangement for a planted tank due to specific requirement.
Aesthetic aside, the overflow arrangement must ideally be as silent as possible, and, for planted tank specifically, turbulence should also be as little as possible.

To reduce noise, the Durso design is very good and fail safe.
Unfortunately, this result in a lot of turbulence as air is drawn into the overflow and this may result in excessive CO2 loss ( yet to be verified ).

You should refer to the following link for a better understanding of the various overflow pipe design.
http://dinardiengineering.com/blog/?p=34

Note that the Herbie design solve both the noise and the turbulence problem.
But having Durso may not meet your aesthetic aspiration for a planted tank.

Note that the diagram you see in the link's Herbie design is flaw and will continue to let water flow into the sump when the return pump stop.

If I were you, reverse the arrangement such that the lower pipe is extended up to the water surface and act as an overflow ( 5% of flow rate ).
You can even improve it further by retro fitting a surface skimmer just below water surface such that during normal operation, 5% or flow will go through the slot of the surface skimmer.
When there is abnormality causing water level to rise, the top opening of this surface skimmer will act as the ultimate overflow.
At the Durso pipe, 95% of water will flow ( using valve to control ).
To solve the inherent problem of air being drawn into this pipe, turn the air inlet of the Durso into the water surface ( U turn and let the opening go underwater say 5 to 10 mm ).
This is very important such that when the pump rate reduce for whatever reason, water level will drop and the expose air intake will draw air in and break siphon.
Note that this air intake's opening cannot be too low into the water surface.
Make it at least half way up from the bottom of the horizontal section of the Durso such that when pump restart and water level begin to rise, water will begin to flow through the Durso BEFORE water level reach the opening of this air vent and block it.
This is to prevent airlock in the Durso whenever you restart your pump.

Note that in this arrangement, you have 2 visible pipe in the tank.
Also, to prevent small fish or shrimps being drawn into the sump tank via the Durso pipe, you may need to fit some sort of pre-filter at the opening of the Durso pipe.
All this will have an impact on the aesthetic aspect of the tank.
One way ( which I will do myself later ) is to move the Durso outside the tank.
If you have space between the back panel of the tank and the back wall ( assuming you have a wall behind the tank ) then there is an opportunity to do this.
What you do is, instead of the Durso rising up in the tank, you connect the Durso from below the tank where the hole is suppose to drain to the sump, going behind the tank and make a U turn at the water level height behind the tank and down again back to the sump.
Remember to install the air vent that will turn into the tank from the top and into the water level as described above.
This air vent together with the level of the horizontal member of the Durso is to break siphon.

As to the intake for the Durso, you can use small pieces of acrylic plate to barricade the area at the bottom of the tank such that the height of this barrier is a little higher than the eventual maximum height of the substrate you intend to lay.
On top of the opening for this outflow position, use some kind of sieve with suitable sized hole to cover the opening, then lay on some gravel up to nearly the height of the barricade.
This will be where water will be drawn into the Durso.
The barricade and the gravel is to prevent substrate and fish/shrimp from being drawn into the Durso pipe and sump tank.

The 3rd hole can be used as drainage for water change.
If you cannot pre-plump permanent drainage pipe for water change purpose, this will become a spare outlet.

Too bad I am not good at computer graphic drawing, or else I can illustrate the above for easy understanding.

Sound complicated, but I assure you its worth the extra effort

Hope it help.

Cheers!

BT Lee

[bossteck]

Hi BT Lee,

Thanks for sharing.

I tried my best to read the link you provided, but may have missed some parts of it.

Can I find out how, in the Herbie design, would the siphon pipe not drain the tank in the event of pump failure if there is no overflow compartment?

I would think that you will defintely need a overflow compartment to prevent that with this design.

[BT Lee]

Dear Eric,

Hahaha, very sharp observation.

I was earlier misled by the drawing as well, luckily realise it later and correct my posting.

The writing appear to be correct as it says a siphon pipe, meaning one that U turn and the opening goes below water surface.
Somehow the drawing did not reflect that.

Note that my recommendation make this 'siphon' a Durso pipe when water level falls below desired level by retaining the air vent but make the air vent do a U turn as well such that when tank water is at normal level, this air vent is blocked and therefore no air drawn.
When water level fall, air is drawn like a Durso and siphon breaks when water level falls half way below level of horizontal member of Durso.

Cheers!

BT Lee

[mozesyap]

wow. Thanks for your information BT Lee, I definitely learned a lot there. It looks really complicated but I sort of get the concept of Durso overflow method..

So you are suggesting doing the Herbie but having the arrangement reverse compared to the link? And having the durso work like a durso whenever the water level reach a certain level, using the air vent below the water surface to control that? The open overflow will act as more of a fail safe?

I am lost when you mentioned moving the Durso out of the tank though.. Anyway it is probably too technical for me, mechanical engineering has never been too intuitive to me

I haven't ordered the tank, so I would take your recommendations into consideration and probably consult whoever my tank maker is.

If these arrangement takes care of the noise of the sump, it is definitely where I am going.

A bit worried about whether a 5x2x2 with a sump below will get approved by HDB or not..

[mozesyap]

double post

[BT Lee]

Dear Mozesyap,

Hahaha, glad to hear that I did not confuse you on the 1st. part of the overflow/siphon arrangement.

The part about moving the Durso outside the tank is my own idea.
Lets see if I can explain it better this way.

Instead of having the siphon/Durso connected to the bottom opening inside the tank, connect it to the bottom opening outside the tank where you normally have a short pipe to drain water into the sump.
Since the bottom opening outside the tank go downward, you make a U turn at suitable position between the bottom of the tank and the sump and let the Durso assembly stand up between the back panel of the tank and the back wall.

The highest point of the horizontal opening should be ideally a little below normal water level.

Of course you will have to extend the length of the pipe to allow water to flow into the sump.

To ensure less agitation, I submerge this outlet of this pipe in the 1st compartment of the sump.

Note that the small air vent's opening’s level is very important in this arrangement to prevent air lock from blocking the restart of siphon.
The opening of this air vent ( U turn into water level ) should be substantially higher than the lower level of the horizontal opening hole ( but below the top level ) of the Durso so that water can flow into the Durso before the rising water level in the tank seal off this air vent's opening. Again, take not to ensure that the highest point of the horizontal opening in the Durso/siphon assembly is a little below normal water level to ensure automatic restart of flow after siphon break due to lowered water level.

The open end in the tank where water enter the Durso assembly ( outside the tank now ), will become the intake point of the sump filter.
My suggestion is to make suitable partitioning at the substrate level to ensure that substrate is not drawn into the sump.

Hahaha, think about it, I am sure you will understand what I mean.

Cheers!

BT Lee

[BFG]

Mozesyap, how do you want the tank to look in the end? Would you want to see a tank with 1 corner with overflow box or 2 corner of the tank with overflow box or no overflow box in the tank at all? If you want a clean look without overflow box, it can be done.

[mozesyap]

Hi BFG,
Guess I would still have a lot of decision to make actually I prefer to have an overflow box. Not sure why but it somehow makes me feel safer
it will probably be at the back of the tank. I have at least a 15 - 30 cm gap between the wall and my tank.. so I would have a lot of options.

A bit worried about livestock going into the overflow box though..

What's the pros and cons of having an overflow box?
Here's what I can think of

Pros
It would hide all the pipes for the sump system.
And if there's major pipe leakage only the overflow box will get drain fast.. so reducing the chance and speed of a flood (no sure about this happening though)..
Less chance of clogging up?
Easier to maintain?

Can't think of more...

Cons
Takes up a lot of space that can otherwise be used meaningfully?
Traps live stocks?
Aesthetically not very pleasing..

[BFG]

I hate my overflow box in my marine tank, too distracting when viewing the tank and it disturb the water flow compared to a tank without overflow box. You could get away without the need to use overflow box by using something like the one in the link I provided if you can find it locally.

http://www.absolutereef.com/forums/i...dpost&p=194208

Hope this helps!

[BT Lee]

As suggested by BFG and similar to the arrangement in the link, you can find the detachable overflow box in Aqua Marine.
Made of clear acrylic, very well constructed.
That way you don't need to have bore hole at the bottom of the tank.

Take your time, don't rush.
80% planning; 20% execution............

Cheers!

BT Lee

[mozesyap]

Interesting. Thanks for the link.
Yup,I am renovating my place. The tank will probably be the last thing and the current plan is to start it next Feb.
So right now it is all planning

[mozesyap]

Ok I guess I will do more investigation on the sump/ the detachable overflow/ the herbie setup..

Back to one of the other question. The chiller.

How should I setup the chiller with the sump? Maybe some of the reefers will know better..

Would there be any problem with just setting up the chiller with the sump, would there be a big difference in temperature between the water in the sump and the water in tank if it is setup that way?

[BFG]

What chiller are you going to use? An aquarium chiller or a aircon compressor chiller ?