[mr.wilson]

I was responding to the comments that Canadian had made about Vortechs. Vortechs are easily the best powerhead on the market, if you can still call them a powerhead, more of a magnet spinner. They address most of the problems that submersible pumps cause. If I was talking about Tunze pumps I would have address different issues.

The only reference I have of sound was from the Dana Riddle article where he claimed they have a whine which increase in frequency as they power up and down. I've seen them is use on tanks, but only in fish rooms or noisy hobbyist tanks.

Tunze powerheads can be located anywhere, but they need to be removed for periodic servicing and they have moving parts in the reef. I don't agree that magnet coupled chemical pumps with sealed bearings such as Iwaki require preventative maintenance or volute cleaning. It appears that you experience is limited to non-chemical pool pumps like the Sequence line, so I understand why you don't like closed loop systems. This line of thought is equally as unfair as me comparing a Vertech pump to a maxijet, which I have not done.

I'll admit some of the issues I have listed are not significant drawbacks, like extra power cords, but it was a simple comparison of pros and cons just as I would accept that Dart pump is too loud for a home aquarium and it isn't suitable for marine applications.

I agree heat transfer comparisons are splitting hairs. I was just using Dana Riddles comments about heat in comparison to Canadian's claims of added air conditioning costs to counter the heat thrown from a closed loop pump. They both have external temperatures of 130F, it's just closed loop pumps use heat sinks and fans to mask the heat. You could easily put a fan on a Vortech if it was ever an issue, and I doubt it would.

I don't have the time or desire to look up articles about vibration or moving parts in reef aquariums. They may or may not affect the physiology of fish and invertebrates, but it remains as something to consider when weighing options. Your claim that you can tell it doesn't effect your fish is silly.

Turbulent flow doers not create random flow patterns. They may be more intricate, but they are not random unless you have programmed sporadic sequences into your powerhead controller.

You have to make up your mind about the flow you are endorsing. One minute you are talking about prop powerheads offering lower velocity and fanned out, diffused flow as being beneficial, and in the next paragraph you are saying a closed loop pump has too much velocity so it moves too much water as it passes through the tank. If it moves more water than the amount measured leaving the effluent port, then let's add that to the total flow rate as we should.

My point about pump access with a closed loop was you unplug the pump and shut off two union valves and you can remove it to service, upsize or downsize. With Powerheads you may have to move corals if you have them within the rock work. Vortechs are easy to access because they don't work in these locations and don't utilize suction cups or plastic clips.

In my mind quality power heads like Tunze and Vortec offer the following advantages over CLs.

1) Easier setup and maintenance

Easier set-up, harder maintenance. Closed loop owners forget they are even there, while powerheads are part of routine servicing.

2) Better resale and easier to incorporate in new tanks. Plumbing for a closed loop is expensive, I did a 4W OM on a clients tank and it cost around $400, very rarely can plumbing parts transfer to a new tank.

I don't know which would have a better residual value, but it's a strange benefit to consider. For that reason, I'll give you the point.

3) Can be relocated at anytime with minimal effort

Absolutely, but you will never get it where it works best.

4) Can be upgraded or down graded without major modifications to the tank

Just as a closed loop pump can. A 1" in and out port will fit hundreds of pump possibilities. Once again, planning for re-engineering is a poor selling point.

5) Use less power, greater efficiency a dart runs 22.5 GPH/W while a Tunze Stream 6000 runs 123.2 GPH/W

This is only true if you are measuring strictly the water exiting the effluent port and not the overall effect. The trade off with high volume low energy consumption pumps is velocity. There are arguments for both high and low velocity systems. Closed loop systems can simultaneously offer both with a wave making device, while powerheads are limited to low velocity, lower velocity, and no velocity. Energy savings are nominal. While they may be 50% in the best of scenarios, the hard number is $5-10 a month. In a society where we drive cars that get 20MPG while 60MPG cars are readily available, it's a hard sale. How often do you fill up your BMW gas tank? Whatever you are spending, it's three times higher than what it could be.

6) Create less noise, sorry but a tunze is quieter than a dart

Once again if you are going to compare to a Dart then I will use an oil cooled cast iron sump pump as a basis for powerhead comparisons An Iwaki or Panworld 70 located in a remote location away from the cabinet will not be audible at all. Alternatively a Red Dragon, Deltec or Poseidon pump is also inaudible.

7) Much better flow control and have better capability to produce more natural wave flow. The vast selection of electronic controllers is far superior to the OM and SCWD devices which are only ones I'm aware of.

Then you have proven once again that your knowledge is limited.

8) Simplicity, closed loop systems require more experience in plumbing.

Absolutely, just as proper Tunze Stream placement requires more experience than putting them in the corner where they look good.

9) No tank modifications needed, Closed loops require a swiss cheese tank to hide the plumbing

There is no reason why a closed loop system with an external pump requires and holes in the tank. If you can live with powerheads in the tank and hanging off of the side, then a few pipes running over the trim at the back should not be a problem.

10) Better reliability all the way round. The external plumbing required for a closed loop can be a dangerous game, bulkheads can leak down the road and replacement would be a tremendous headache requiring the complete dismantle of an established aquarium. People worry enough about the actual tank seams leaking, why add more potential for leaks?

First of all, I was right, there is always a #10. You are absolutely correct, a tank full of extra valves, fittings and bulkheads is a liability, especially if it is not done properly. It's a very small liability, but it still exists. A closed loop system with external plumbing running over the trim saves the cost of extra holes, bulkheads and valves. I see a need for only two drain holes with anything else being a luxury. Doesn't your tank have four holes in the bottom? This adds the extra cost of tempering and or a thicker bottom panel. The bottom is the easiest panel to get a leak with as there is more hydrostatic pressure on it and long pipes can bend and cause water to leak past the bulkhead flange.

I could go on but 10 seems to be the magic number.

At least we agree on something