frogspawn vs. brain

[chvynva916]

Recently my green brain has begun to recede. My frogspawn (doing well), is about three inches away at the closest. I have never seen sweeper tentacles extend even within an inch of the brain. Could I be missing them? I have been meaning to move my brain off its ledge into the sand anyway. What do you think?

[Dave ESPI]

I have a similar issue.... BUT I relised its cause of powerhead under currents that are flowing from the ledge and microbubbles iritating the flesh. Look at PH and water flow first... it might be an issue. ALSO could be a Strontnium or Mg, defficency as such was the case in my tanks.. it has stableized..... I hope to see regrowth in a few weeks...

[chvynva916]

YES!!! I just installed a new power head and it is still spitting out micro-bubbles. Will this stop? Is this what is irritating my brain?

[MrConclusion]

SOme powerheads will always spit bubbles, some will tend to do it whenever they're clean.

 

If the impeller isn't drawing air, the source of the bubbles is blade cavitation. The trailing sides of the impeller blades create low pressure zones, which cause dissolved gasses to precipitate.

 

All impellers are speed regulated by the frequency of household current, so there is no practical adjustment for blade speed.

 

The tendency can be greatly increased or reduced by the design of the water flow in the impeller chamber. Unfortunately, some of the more efficient designs (the most GPH per watt) have the highest pressure differentials.

 

Try changing the flow rate setting. Some pumps have a sweet spot you can find, or a bad spot to avoid. Most flow rate adjustments are intake restrictions, so you'll be lowering the "high" side of the pressure differential.

 

If that doesn't work... see what happens if you restrict the output side. You can also open the impeller housing and try to smooth out any sharp edges if there were molding irregularities. Use and exacto knife or a hot tool like a soldering iron, but be careful!

 

You can also attack the problem from the supply side. I have a lot less data behind this, but it might work. Micro bubbles (if not caused by drawing atmosphere into the impeller as with a protein skimmer) are usually CO2 and sometimes nitrogen, which are produced in the tank in such abundency that they must diffuse from the surface into the atmosphere. As dissolved gasses become saturated, you have a greater tendency of pressure differentials precipitating gas bubbles. In some cases it may be possible to increase your surface movement so that more gasses are transferred out of the aquarium.

 

Sorry to raise more questions than answers. I hope that helps you in some way. I can also tell you that in my experience, Via Aqua, Micro-Jet and Mini-Jet pumps, and Marineland powerheads seem to cause fewer bubbles than Aquaclear or PowerSweep powerheads and RIO pumps... although I'm not trying to say anything else about the relative merits of those products... and it could be that variations in application made the difference.