Foam and Water Surface Tension

[wchp]

Now about 8 weeks into this and things seem to be coming along nicely. 46 Gallon Bowfront with RemoraC Skimmer and 50lbs live sand and 40 lbs live rock. Three different damsels and a couple of mushrooms.
All measurements are great.
Trate/Trite 0, Ammonia 0, PH 8.3, Alk 3.8, Cal 390 Temp 76
Running Daylight at 8 hours and Actinic for 10 hours.

Only thing I have noticed of late. Skimmer is producing about 1/4 container skimate daily, but as each day passes after a 10% weekly water change, the surface tension seems to increase and foam forms in the back corners(where there is limited water movement)
What causes this and would this be considered normal?

[Don_Gnomio]

what you need is better water flow, and to keep the surface of the water agitated, you do this and it should go away...

HTH
Victor

[skylab1]

The reason you have foam on the corner is because you have too much protein in the water, your skimmer is not taking all that protein away.

Water flow is very important, your flow rate should be at min. of 6 time of total gallons of water and no more then 10 times per hour. So, a 46 gallons tank like yours should have a min. flow rate of 276gph and max of 460gph.

At 6 weeks old, there isn't enough bacteria in your tank to take out all of those protein. You can wait a few months for enough bacteria to develop or you can add some to the tank and take care this problem now.

I don't know if you have a sump or use a canister filter, but if you do, place your return above the water not below it. Have the return water spray across the surface of the tank, this will increase the rate of gas exchange and bring more oxygen to your tank water. Bacteria need lots oxygen and so as fish, if you are using hang on the back type filter then add a good air pump and heave duty airstone to "boil you water" with air bubbles. Anything you can do to increase the oxygen in your tank will help a lot.

[wchp]

Hmmm.
I have a Whisper 60 that I just have Bio Balls in and a "bio filter mesh" that I have heated the bottom edge of the drop shoots with a heat gun and angled them so that they force the water across the top of the tank (to the point that there is a slight upward swell on the front of the tank)
I Have two power sweep 214 power heads with their diverter fans installed that force water up to the surface AND they have the snorkels installed so they make a LOT of bubbles. And the Remora C skimmer with the pre skimmer pulling water off the surface and this is being driven with a MaxiJet 1200.

So If I am hearing folks right, it need yet MORE water flow at the surface?

[skylab1]

No, not just water flow at the surface. The turn over rate is equally important as well. Your Whisper 60 has a flow rate of 330gph which s about 7 times of turn over rate of your 46G tank so that's good. With water fall type of filter like the Whisper, place something in the water’s path so the water is a broken flow rather than a smooth flow. Much like rocks in a water fall.

The reason for this is very simple. Bacteria and your organisms (fish and inverts) respired. They use Oxygen and expel Carbon Dioxide. Your water does not care if Carbon Dioxide or Oxygen is present. The return tube splashes the water across the surface, like small swells and waves in the ocean. At no time, is the water in the ocean still. There always in motion. This area, the top of the water is where most of the gas exchange occurs.

The Carbon Dioxide is driven off, and expelled from the aquarium BEFORE IT IS DISSOLVED INTO SOLUTION! Since a vacuum of gasses now occurs in your tank water, Oxygen (air) fills that vacuum.

If you can try place your power sweep 214's return above the water surface, turn the diverter fan to force the water down instead of up. This way the return water can spray across the surface of the water back and forth.

The only thing left is you need more bacteria to eat all that protein.

[swims withthe fishes]

I would say you most likely have bubbles on the surface due to the air bubbles presented by the powersweeps. your remora should be efficient at removing the protein on it's own. but you are creating a "skim" within the tank by introducing bubbles. protein will not just show up on the surface by itself, it requires contact time with air to pull it out of suspension. it is getting this from your introduction of air through the PH's. take off the air inductors.
i used to keep my sweeps turned sideways in my 38 to create a flow up and down instead of left and right, this way at differnt rates they both break the surface for a second out of each rotation. i used them without the diverter fan they come with, but it should work with too if you like. the use of anohter PH in the center of the back of the tank blowing forward will create a killer change in waterflow constantly around the tank, especially in a bowfront.

good luck,
chris