Called up EuroReef and ordered a new modified Eheim 1260 recirculating needle wheel pump for my RC-500 skimmer. Frustrating and annoyed that I have to keep tossing money into this skimmer, but the performance is amazing and the skimmer is totally worth it.

Drained out the EuroReef RC500 skimmer (holds about 8 gallons of water). Removed both SP4 recirculation pumps and inspected them. On the pump making the loud noise, I found the impeller shaft had cracked into two parts causing the magnet to bounce around.

This is the 4th impeller that has broke in this unit and they are expensive to replace. I'm going to consider swapping out the entire pump for a modified Eheim 1260 needle wheel pump instead. This is a very expensive upgrade but I'm hoping the impellers will last longer.

Used all my test kits, and everything looks pretty good:

Temp: 78.5 F
pH: 7.92
Conductivity: 53.8 (35.5 ppt)
ORP: 300 (upward trend)
Calcium: 440 ppm
Alkalinity: 8.5 dKH
Magnesium: 1200 ppm

While the ORP looks low it started out in the low 200's, it is on an upward trend with peaks to around 320.

Cleaned the EuroReef RC500 skimmer and cleaned out the SP4 recirculation pumps. Upon putting everything back together it made a horrible noise. I couldn't solve the problem, I left one of the pumps turned off until I have time to drain the skimmer and open up the pumps again.

Installed the new temperature probe for the AquaController Pro, calibrated the pH probe and installed the ORP probe. The first issue I noticed is that the temperature probe seems to be 2 degrees off on the low side.

As an interim fix, I programmed the AquaController Pro to add 2 degrees to the readout displayed and send an e-mail to Neptune Systems for clarification as the instruction manual hints that the probes are factory calibrated.

Ordered an ORP probe for the AquaController Pro, not that I needed one, just wanted one. An ORP probe provides a number somewhere between 200 and 500 where the higher the number the better. The important thing is not the actual number but the trend over time. For example if its always around 325 to 350 and one day its at 200 I would give the tank a close inspection looking for something wrong such as a dead fish.

The temperature probe on the AquaController Pro failed which not only resulting in "low" temperature alerts and engaged the heaters, but it is also the reference probe to the pH controller and conductivity controller.

The loss of the reference to the pH resulted in the calcium reactor being taken off line and tripping an alert of high salinity.

None of these are critical, just had to recheck levels manually with test kits and remove the calcium reactor and heaters from the switch boxes until a replace probe arrives which might take a week or so.

Performed another round of manual removal of the bubble algae. I'd say I removed about 90% of everything visible that could be removed. I have plenty in harder to reach areas that I'll have to leave for now and see if the urchins make a difference and possibly get some emerald crabs as well in a few weeks.

I've been toying with the idea of adding some urchins to deal with some of the smaller bubble algae and help promote coralline algae. Today at the LFS they had two so I picked them up.



This picture shows them helping themselves to some Xenia I had growing on a patch of rocks.

Various bubble algae have taken hold in the tank and seemed to have run rampant over the past month. It's not the worst plague I could get. Between manual removal and herbivores it can be solved.



This one looked like a tomato growing behind a rock.



While most of the bubble algae is annoying and harmless, they can take out entire corals when left unchecked.