Internal Filter, surface skimmer and heater unit: Feasible?

[sweevo]

I'm in the process of doing research into my next reef tank upgrade. I'm not far off decided on what my tank and equipment will be now but i'm thinking of adding a little bit of DIY magic into the mix. I just wondered if any of you could just say whether you believe what i'm going to try and do is feasible or just plain daft.

My new tank will be a 24" cube

I'm going to go without a sump this time and try and keep things as simple as possible regds equipment.

I'm going to opt for a Tunze Internal skimmer but i'm also thinking of making my own internal filter and surface skimmer which will incorporate a heater. Tunze do make a Nano Cleaner which does the surface and mech filtering already but think I could make one myself using the same design but with much greater flow. This is where you come in.

My plan is to make an internal acrylic over flow box that will sit centrally at the back of the tank. It will run all the way to the bottom of the tank, have four sides, an acrylic base and have a combed overflow along the 3 of the top edges. The overflow will be ALMOST totally submerged/overflowed when the power is off and therefore always holding water. The unit will attach to the back and bottom of the tank using suckers, that way it can all be removed at a later date for maintenance if required.

I then plan to install a high flow powerhead ( Seio M620 2400lr ) that will sit at the bottom of the overflow box with the end of it's nozzle pointing out of the box towards the front of the tank through a drilled hole driller/cut in the box. The hole will be sealed with silicone around the PH nozzle so the only way out at the bottom is through the PH itself.

My theory on why this will work ok with a highflow PH is because:

1: There is no head pressure on the powerhead.

2: Due the weir being partially submerged, the water level in the box will be the same as that in the main tank at all times so water will freely flow into the box as water at the bottom is expelled by the powerhead. As long as the weir can provide a flow of water into the box equal to that that the PH can expell it will never run dry.


I intend to use some eggcrate as a cradle for filter floss at the top of the unit for mechanical filtration and skimming the surface. I also plan to install two heaters in the unit as the flowrate over them (if this will work) will help heat the tank more efficiently.

So, will this work or am I just plain bonkers?

I know I could use a sump etc but I don't want a sump this time around so please don't try to convert me back. My mind is made up on that aspect.

All comments and input appreciated whether positive or negative.

Here's a diagram if I've confused the hell out of you all too!





Many Thanks.

[yeldarbj]

Two things to take into account:

1) I think you will need to get some type of waterfall effect to really get the surface skim that you want. With the grates at the top in your drawing, water under the surface will flow into the "filter", but the actual surface "scum", might not get pulled down into the water column inside the filter. I had similar problems with an AquaC Remora surface skimmer box.

2) Make sure you can remove the powerhead for cleaning, if it is siliconed into the hole, that might be difficult.

Drs F&S sell a cheap (~$13) surface skimmer made for cannisters. You might be able to work it into your plans. I have one, and it actually works pretty good.

[sweevo]

Thanks for the reply yeldarbj.

Know what you mean about maintenance. Silicon was the only way I could think of getting it air tight. I was worried that a rubber seal might perish over time and possibly leech nasty stuff into the reef.

Your point about the needing a waterfall effect is something I hadn't thought about though. I thought it all looked too straightforward!

I had looked at these surface skimmer attachments a while back but I thought I could be clever and make an all in one unit just using a high flow PH.

Do you think adapting my filter something like this might work using one fo these surface skimmers?



The way I understand these things work is that the water id drawn throught the surface skimmer at both ends by water which is flowing down through the filter. Like the arrows in my diagram. Is that right?

Looking at the image on DrF&S's website it looks like the little weir just floats so that only the surface layers are drawn in through the cap end of things thereby skimming the surface and passing the gunk through my filter.

[leebo_28]

I don't think you will need the skimmer attachment at all. If the ph is strong enough , it will drop the surface level enough to "skim" the top, that should be the only source of water going into the "box" IMO. Very nice idea to go with ,but are you worried you will have to do to much cleaning(floss and such)?

[leebo_28]

Also , is this going to be a bare bottom tank?

[sweevo]

I was thinking of going BB as that's what my current setup is. It originally had 1" of Caribsea but after 12 months there was as much gunk as sand in the bottom of my tank and my NO3 had started to climb. In the end hoovered it all out with a syphon tube.

With regards to the floss I was just thinking of replacing it on a weekly basis and throwing the used one away. I do this on my current reef to stop the media going bio and potentially forcing the NO3 (etc) up.

I guess the closer I match the weir overflow capactity to my PH max o/p the larger the drop over the weir will be? Am I right in thinking that? I was thinking that if the overflow could supply twice the flow of the PH there's little chance of the level dropping inside the box as the sheer flow will dwarf all that the PH can do... Been a while since I did science at school !!!!

I've had a new M620 arrive today for this project and have the odd spare tank lying about the place (bet i'm not alone in this!) so I guess I could do a quick experiment with FW and find out. Just need to find a suitable container.....

[sweevo]

Decided to give it a go before I went to bed otherwise i'd just have been lying there thinking about this all night!!!!

Leebo_28, you were right! The water level in the container does drop slightly so surface skimming will work. I used an old cube shaped tupperware container as my test overflow box, my QT tank with some FW. The tank was filled enough so that the water level submerged the container by a couple of millimeters before the PH was turned on. Turned it on and bingo!

Noise could be a problem (always thought it might be) but I guess I can work on that when the time comes.

Got a couple of pics of the bits and pieces (in case anyone's not sure what i'm on about!) which i'll post tomorrow when I get time.

Thanks for all the advice guys.

[bues0022]

The drop will become more significant with increased evaporation also. Just make sure to keep this in mind because if you don't keep up with an ATO or a keen eye, the resulting waterfall will either keep you up at night or sending you running to the bathroom every 10 minutes! Your thought on the heaters is mostly correct...I don't know for sure since I don't have data on it, but I doubt that in a standard setup that the flow rate around a heater is small enough that a large thermal boundary layer will buildup thereby reducing the heater efficiency. What the moving water will do, however, is help keep the tank temperature more constant and you won't have a hot/cool side of the tank near/away from the heater. Cool ideas though.

[sweevo]

bues0022, I'm going to get the Tunze Osmolator for my auto top up for the new reef but thanks for double checking. On my current setup I have a HOB kalk reservoir which connects to a float valve in my sump. It's worked a treat for the past 3 years but with no sump in the new setup I'll need a sensor and pump rig for sure.

Here's a few pics of my prototype. You'll notice the box isn't sat flat on the bottom of the tank in one of the pics. When I tested it I just pressed down on the container so it's base was flush with the floor of the tank. Couldn't be bothered drilling holes and attaching suckers etc.

[leebo_28]

keep us posted!