Brown Gunk on Water Surface

d2mini

Premium Member
Anyone else experiencing this in their AIO tanks?
I have the 8g Cadlights and the water surface is nasty.
If I stick my arm in the tank, it comes out covered in putrid brown stuff.
It's a film on the top of the water.
I'm so used to my coast to coast overflow with thousands of gph of flow on the big tank. The flow on these little things suck. If I look at the surface of the water, it's just spiraling around, yet there seems to be decent flow through the overflow teeth, which are clean btw.

Any way to remedy this?
 

d2mini

Premium Member
Ya, i have an MP10 in there. :)

It definitely needs more surface skimming, no doubt.
Can you point me to something? Either I'm not seeing it, or I'm not understand how what I am seeing works.

I thought the overflow teeth I have is technically a surface skimmer but the pump doesn't seem to create enough flow for it to work. And I already have issues with the return flow blowing sand around without partially blocking it with my rock structure.
 

d2mini

Premium Member
that's the problem, the return nozzle just sticks straight out of the middle of the back wall.
 

AdamNC

New member
You will need to change the return nozzle to a ball socket nozzle so you can point it up. And possibly use a ball socket flexible tube also.
 

d2mini

Premium Member
where do i get that?
Briefly looked when i first set up the tank but couldn't find anything that would work.
 

elwaine

The mad reefer
Dennis,

One problem with the CadLights mini tanks is their poorly designed return. As suggested above, without the MP10, you'd have to modify the return so that the flow stirs up the surface of the water. However, before you do that, elevate the MP 10 so that it churns the water surface enough so that you see the shimmering/rippling effects in your lighting... similar to what you'd expect with halogen lights. Your Nano Box Mini Tide has multiple point light sources and gives the same patterns you'd see with halogens.

If the churning of the surface doesn't work to rid the gunk (and I doubt that it will), you'll need to get a protein skimmer or remove surface water when you do your water changes. But removing surface water (skimming) during water changes can be a PITA, so a protein skimmer is likely to be the better option.

(See my PM)

_Larry
 

hersheyb

Active member
I had the same problem when i had my 8 gal cadlight. Aside from what everybody here mentioned I also reduced the water level in back chamber to about 1/2" which the broke the surface water as it went over the overflow.
 

Radioheadx14

New member
I have the 18g mini II. I also had a bunch of gunk on the surface. I was tired of skimming it every day, and after constantly messing with the pump flow, I decided to cut out 2 of the overflow teeth (non adjacent to eachother) to allow better flow thru the overflow. the surface gunk was gone with in a minute and the tank looks cleaner now. While it looks a tad ghetto, it works well... the overflow teeth should have been wider from the start.
 

elwaine

The mad reefer
Good point Radioheadx14. I had a lot of trouble with the new CadLights 8 g mini 2. The slots were so narrow and so few in number that I had to turn their own stock pump to the lowest setting to prevent the water level in the display area from reaching the very top of the tank. What a poor design.

I spoke with them about the problem and their solution was foe me to widen the slots. Is that hubris on their part, or what? CadLights takes no responsibility for their own errors.

Long story short: I removed the filter area, turning the tank into a nice 8 g cube which I will use for a freshwater aquarium. I then bought an IM 10 g Nuvo Fusion for my pico reef, and I love that tank. That aquarium has much wider skimmer slots and I have no trouble with surface scum.
 

Radioheadx14

New member
The glass work is great... the plastic divider is cheap, poorly designed, bad pump location and easy to break. But, I love my 18g, especially after moding the overflow.

Like you, I might upgrade in a year when I buy a house and remove the back chamber and drill the tank making it a nice frag tank or a display fuge.
 

Radioheadx14

New member
I used a hack saw to cut thru the 1/4" top to the open slots on each side of a 'post' or 'tooth'. then using a pliers, i just snapped the tooth of. its thin plastic so almost no pressure will break the tooth, leaving a nice overflow opening. for the 18g mini, removing 2 non-adjacent teeth was enough for me to crank the return pump all the way up and have great results. with an 8g, I'd say 1 might be enough, but I am only speculating.

its been a couple days and 0 gunk and lots of surface movement. I have to turn off the return the feed now because its so strong. Night and day different.
 

elwaine

The mad reefer
I used a small diamond coated file. Worked fine. But there should be no reason one should have to modify a tank's overflow. It's a basic feature of any saltwater aquarium, and if it is designed correctly in the first place, it should work properly from the get go.

If the slots are too wide, your CUC will eventually get through the slots and into the back compartments. With all-in-one tanks, it's no easy chore to recover then and get the critters back into the display compartment. It's not like having a tank with a sump, in which you can easily remove the snails, etc., that wandered over the overflow.

A properly designed skim compartment in an AIO aquarium should have enough slots of sufficient width to allow for good skimming while preventing all but the smallest snails from winding up in the back compartments "” where they can die of starvation and pollute the tank.
 
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