melev

I don't know when I got the Dart pump that runs the 400g's return flow (from the sump), but I'm guessing 2011. Maybe it's a newer, because the serial number label doesn't match the image from back then. So maybe 2012. Last night I was working in the tank with the flow off. When I turned on the return pump, it needed a little help to get started - which has been the case for the past week. Using a flathead screwdriver, I can insert it into the driveshaft's slot and give it a small twist and it comes to life. This has happened in the past, but after a few days it was back to normal without intervention on my part.

As I sat at my desk, I heard the tank's sound change and noted the pump wasn't moving water. Gave it another nudge, and it burst to life for about 10 minutes. Then it stopped. This is rather unnerving since the return pump should always be on 24 hours a day, unless I turn it off. I've had a backup pump ready for this day, so I commenced to get everything in place to make the switch.

In the backyard, I retrieved one of the 55g barrels and rinsed it down with a hose. Basically I needed to wash off what winter had done, including leaves and mud that was amassed around the rim. When I tried to bring it into the fishroom, it was wider than the doorway I always use. I had to take it out front and in through the garage door and then into the fishroom from that larger door. I also had a Mag 9.5 and some 1" tubing to move water out of the sump into the barrel.

It was around this time that I remembered that I'd plumbed the system four years ago for this incident, where I could change two valves to restore flow temporarily during this exact situation. For 15 minutes, I had the second pump that runs the manifold act as a return pump as well. Then I powered it down and began the process of pumping water out of the return zone until the water was lower than the bulkheads.

Loosening the union connections, I was able to remove the pump from the plumbing.

Those fittings were transferred from the old (black) Dart pump to the new (grey) Hybrid Dart pump.

Then they were tightened by hand and the sump was refilled. The pump was then turned on again, and I observed the system for a couple of minutes. That's when I noticed some water trickling across the floor from the sump.

It only took a few seconds to see I didn't tighten the union enough, so using a large pair of channel-lock pliers I tightened it a few more turns. No more water trickled out of the fitting, so the water in the drip pan simply had to drain out quietly overnight. That puddle worked its way to the french drain as designed and by morning it was nice and dry.

It was obvious that the tank had more flow from the new pump as the surface was really rippling hard. But I didn't notice until this morning that it was moving so much water that the sand 6' away was moving and covering up corals.

The corals have been unearthed and the sand leveled out some, but at the time of this writing I need to do it again. It should settle down soon. I'll be watching the corals closely to make sure the flow isn't a problem, specifically the staghorn acropora near the water's surface since it is closer to the penductors.

Another thing I noticed inadvertently is that the reef has been running hotter than normal, no doubt because of the failing pump. Here's the past seven day's worth of temperature data. Normally my reef runs 77-79F daily, but it was already over 81F and it's only April. Click the image for a full size graphic:



The tank already measures 1.5° less today than it did yesterday and the ambient room temperature is the same. So the pump replacement was definitely a good thing.