Custom Scrubber/Sump questions

[tottenham12712]

Hey all I made a post on another site about this but I figured I should post it here as well to get a bit more input regarding my design.

This project started because my tank is over stocked, it was originally a planted tank but due to algae issues it became a unplanted tank. Ive had Diatoms for 3-4 months now and decided to find out why. Upon calling the water company they average 15-22ppm of silicates, that combined with my high fish load causes algae issues. (I need to do 50% water changes weekly to keep the Nitrates in check, about 10-15ppm increase per week)

So Ive decided to build an algae scrubber/sump. It will only have a small amount of filter floss to catch the big stuff, all other filtration will be done by the gravel (BB) and the algae. Heres my plan:

http://i1124.photobucket.com/albums/l571/dzeleski/WP_000192_zps0ef9bab6.jpg

Now the cross lined area will not have water it will be boxed out, should I just allow the algae scrubber to dump into that entire area (unboxed) or give it a small area to pour into (boxed)?

Ill be using 4 660nm Red leds and one 455 blue led. The flow rate on the scrubber should be around 250gph a little less should be ok as well.

Does anyone see any issues with my design? This is a 29 gallon main tank with a custom sump of L16 x W8 x H17.

Thanks in advance!

EDIT: Forgot to mention this is a fresh water tank

[SantaMonica]

Welcome.

Well the first thing is to make it 2-sided if you can. Not sure about the box area.

[Floyd R Turbo]

red flags are flying up. Have you ever designed a sump before? not trying to be demeaning so don't take it that way - but you have to account for power-loss draw down of the display tank. The way you have this drawn (which my just be a rough draft) you will submerge your LEDs if you shut the return pump off. I used to be a freshy so had to learn about sumps when switching to SW so I've been there...

Otherwise - looks like a good start

Oh yeah you have to figure in head loss too. That 250 GPH pump will probably not return any flow to the tank, or just a trickle at best. Then you have to account for plumbing inner diameter affecting flow rate also.

Might be easier to put a scrubber on top of the tank.

[tottenham12712]

red flags are flying up. Have you ever designed a sump before? not trying to be demeaning so don't take it that way - but you have to account for power-loss draw down of the display tank. The way you have this drawn (which my just be a rough draft) you will submerge your LEDs if you shut the return pump off. I used to be a freshy so had to learn about sumps when switching to SW so I've been there...

Otherwise - looks like a good start

Oh yeah you have to figure in head loss too. That 250 GPH pump will probably not return any flow to the tank, or just a trickle at best. Then you have to account for plumbing inner diameter affecting flow rate also.

Might be easier to put a scrubber on top of the tank.

No this would be my first one :), This is a rough draft and Im open to change as only the tank itself is made, but I will box in the LED array with plexi, it will also have a fan on the back to help with cooling. Im trying to make everything concealed in side the tank so I lose less water to evap and see less light outside the box.

The pump is rated for 500gph but at a 5ft head it is around 250 ish, the top of the tank is around 4.5 ft off the ground so I should have enough flow, there will be a ball valve to regulate flow as well. I need the box under the tank as I built the sump around the area in the stand, i dont mind having to spend more on a bigger pump or bigger pipe Also forgot to add ill be using a CPR overflow box.


Welcome.

Well the first thing is to make it 2-sided if you can. Not sure about the box area.

I am going to use a 6x5 inch screen, lit on one side, through my research so far that appears to be enough for a one sided screen. I can always wire another one up but I figured it would be a good start to try just one first. Would you recommend using a smaller two sided instead?

I couldnt find anything on the recommended distance the led array should be from the screen?

Thanks for the input!

[SantaMonica]

2-sided can go twice as long before the roots die. If you can get all the light onto the screen, I'd do 2-sided. Distance will be a function of beam spread; maybe 2 to 3 inches.

[Floyd R Turbo]

One thing to remember is that you only need the sump to operate with enough water to keep the pump submerged. You have to account for level differences when the filter media gets clogged also, in this case you will have a higher water level in the intake side of the sump and lower in the pump side, so depending on how dirty the filter sponge/media gets, you will have to clean it often. Though if you just use ceramic rings or bioballs or a low PPI Poret foam block you will not have this level difference (or not as bad).

Then you have to figure out how much you water level is going to drop in the DT when you lose power. These are your 2 levels - operation and power-off. Operating should not allow pump to run dry/suck air, and power-off should not cause the sump to overflow.

You can encase the heat sink in the sump as you describe, but IMO that makes the system dependent on a fan not failing and overheating, potentially causing a problem. Most likely that problem would be burning out your LEDs, not starting a fire or anything like that, but IMO it would be better to make a bracket on the outside of the sump to slide the heat sink in to and have the fins exposed top to bottom for natural convection in case the fan (if you even need it) dies on you.

+1 to what SM said. If you can find a way to light both sides, do that. Your design is only 8" wide, maybe rotate the screen so that the lights are each 4" from the screen?