Surface agitation?

[CMOS]

Hey All,

I'm a noob to Reef tanks but have been involved in freshwater for over 25 years.

Currently I'm running a 50 gallon tank (30L x 13W x 32" High). I have about 45 pounds of live rock, an Aqua-C Remora Protein Skimmer, and a small Koralia-1 power head inside for water movement. I have this placed about 1/2 way down in depth. I seem to have about the right movement IN the tank, just not happy with the surface agitation.

I'm a big fan of surface agitation in freshwater, so I assume (correctly?) that this is just as important in salt water. My water surface has that merky, stagnant, film on it that just doesn't seem right for any tank, let alone a reef tank.

What do y'all suggest for getting some good surface agitation in this tank? As simple as another powerhead? If so, which one?

Thanks for any input.

CMOS

[Doodaa]

An overflow box and a sump will suck that stuff right off. Move your skimmer to the sump and it should remove it. I had that problem for a while until I figured out the level in my overflow was too high and it wasn't drawing it in. Surface agitation did not help at all in my case. It did open some areas up on the surface, but only pushed the film into a thicker, tighter mat.

[Doodaa]

If a sump is out of the question, I know a few HOB skimmer vendors make a box that fits around the intake for the skimmer that will draw in the surface water similar to an overflow box to the sump and that will help you out too. Here's a link to Aqua-C's version of a surface skimmer pre-filter

Prefilters

[metalhead]

Hey All,

I'm a noob to Reef tanks but have been involved in freshwater for over 25 years.

Same here! Wish I'd made the switch 20 years ago!

Currently I'm running a 50 gallon tank (30L x 13W x 32" High). I have about 45 pounds of live rock, an Aqua-C Remora Protein Skimmer, and a small Koralia-1 power head inside for water movement. I have this placed about 1/2 way down in depth. I seem to have about the right movement IN the tank, just not happy with the surface agitation.

Water motion is a complicated subject and is based on everything from coral/livestock prefs to personal prefs. Personally I like lots of current in my tank. I have a Tunze 6060 and two sureflo modded maxijets in my 100 gallon tank all hooked to a wavemaker. Needless to say these, combined with return flow from the main pump, create some pretty good current. Do some research on what corals you intend to keep and find out what they like... Most SPS prefer lots of alternating current.

I'm a big fan of surface agitation in freshwater, so I assume (correctly?) that this is just as important in salt water. My water surface has that merky, stagnant, film on it that just doesn't seem right for any tank, let alone a reef tank.

I agree, me too. Very important for gas exchange I would say and the film is a very bad thing!

What do y'all suggest for getting some good surface agitation in this tank? As simple as another powerhead? If so, which one?

Thanks for any input.

CMOS

I agree with Doodaa... You either need some type of overflow with a in-sump skimmer or a way to set your skimmer up, if it is HOB, so it will draw water off the surface (skim the surface). After you solve the film problem you can increase your surface agitation by adding another PH near the surface (just make sure it doesn't suck in air from the surface) or by adjusting the output of your return flow from the sump if you go that route. I would definately worry about the film first if I were you though.

Hope this helps and good luck!

[Doodaa]

I don't think surface agitation for gas exchange is as important when you have a protein skimmer running. It certainly doesn't hurt though. It looks like Aqua-C's surface prefilter also has a cup for the skimmer's discharge, so it will change how your tank is flowing. I haven't used that brand so I'm not positive what it looks like in action.

[Seige]

a small Koralia-1 power head inside for water movement. I have this placed about 1/2 way down in depth.

The powerheads you use will depend on how much movement you want.

I have 2 Koralia-3's in my 55 about 3/4 of the way up the side wall near the back of the tank directed slightly above each other so they ruffle the surface.

[CMOS]

Hey All,

Thanks for the replies.

For the record - I have no sump, and don't have the space for it with my tank's small stand footprint.

It sounds like maybe I need to go the route of getting Aqua-C's skimmer Prefilter. I was hoping to avoid putting another piece of equipment in there but, seems it needs to be done.

Thanks for y'alls help.

CMOS

[tholleyh46]

If you move the Koralia up towards the surface of the waterline it will pull a swirl from the surface and clear up that issue without adding anymore equipment. Creates a mini tidal wave, then just aim the powerhead where you want for flow. I do this with my Koralias - works well! Just remember to move it back down some when doing water changes if you leave the power on when doing so as to not run the pump dry and burn it up.

[CMOS]

46,

I have the Koralia-1 model which doe not have a directed nozzle. I already tried to move it to the top but it didn't do a thing. It directs the water radially, not out the front of the unit.

I did order the skimmer box so I'll have the installed as soon as it arrives next week.


CMOS

[Seige]

Wasn't aware of that. Glad I have a 3. Maybe you can pick up a 2 or 3 eventually if the skimmer box isn't enough.

[Ramer]

If you have room next to the tank or else were you could get a 10-20 gallon breeder tank to use for a sump.

[CMOS]

If you have room next to the tank or else were you could get a 10-20 gallon breeder tank to use for a sump.

Ramer,

No room for that where I have the tank, and with the small footprint.

I received the skimmer box today and installed it in about 3 minutes. Within 1.5 hours of install the film on the water surface was gone. I'm looking forward to a more efficient skimmer operation.

I will still probably pick up another small power-head for some more circulation. I'll see what this skimmer box addition does. As of now, I don't have anything that requires "high flow" in the tank.


CMOS

[Seige]

When you pick up the powerhead make sure you direct them roughly towards each other. Otherwise you'll get a cycling action that will create little tornado's in your tank.

[CMOS]

When you pick up the powerhead make sure you direct them roughly towards each other. Otherwise you'll get a cycling action that will create little tornado's in your tank.

Good point.


CMOS

[CMOS]

Hey Guys,

Problems (still). Film on the surface was never gone, just dissipated when I was messing with the tank during pre-filter installation.

After over a week, the skimmer has not pulled any skimmate from the tank. AquaC says that the plastic is probably still breaking in.

It worries me that I'm not pulling skimmate. How long can the tank go like this before I start to see problems?

CMOS

[Doodaa]

They say up to a week for break in, but from my experience, it never takes that long. I don't know your skimmer at all, but you should be able to adjust the flow rate or water level in the skimmer and air intake somehow to get some skimmate.

As far as your surface film...you need to have the water level in the prefilter box lower than the level in your aquarium so the surface water "skims" into it. You do this by raising the box or increasing the the flow through the skimmer.