DC vs AC Pumps. Saftey question?

[CayeCaulker]

I am back after a 15 year absence from the hobby. So please bare with me.

I used to run Iwaki external pumps and plan on running external pumps once again on a 150g tank I am currently setting up.
I see all these new DC Pumps and understand their efficiency but have a few safety questions. I have seen reef systems destroyed by copper contamination from a submersible DC pump that had a hairline crack around the impeller casing. I do not want to risk a system failure due to a DC pump impeller casing crack and do not want heat introduced into the water by a submersible pump. I don't care much about speed control as the application I am talking about is for the sump returns and not for water flow in the aquarium. For feeding I will simply turn off the return pump. I don't need DC power back up as the entire system is living behind a missive APC system and is backed up by a generator.

Do they make a highly efficient DC return pump where there is no way an impeller casing crack could touch the water column. I also have these same concerns on the skimmer solution where I don't have much choice but to use a DC pump for tuning.

 

[DCR]

Most DC pumps can be run externally, but considering your objectives I am not sure why you would want to go DC. They are generally more expensive and the reliability of the driver is another failure point. I also do not see a need for a DC pump on a skimmer. I use a Lifereef venturi skimmer with an external Iwaki pump, but even the needle wheels can be operated without a DC pump. It is just a matter of controlling the outlet water flow and the level in the skimmer.

 

[CayeCaulker]

On the skimmer I can see DC for tuning. However I have not had a skimmer since my old HSA1000's and they used massive pumps and beckett injectors, and I don't really know what I am talking about. I only know what I watch on youtube at this point.

 

[GlassMunky]

keep in mind most DC pumps dont do that great with head height, they drop alot faster than their AC counterparts when it comes to that flow graph. so depending on how far it is from your sump, that may play into things, or not.

 

[YOYOYOReefer]

not sure how a dc pump acts to tune a skimmer? i adjust one valve for the water flow on my skimmer and another valve for the air. The skimmer doesnt care how the water gets to it ac or dc.

 

[YOYOYOReefer]

Caye if you still have that HSA its better than most of what you will find out there in these modern skimmers. they basically came out with needlewheel pumps and now small skimmers are actually pretty good these days and fit under the stand, most are not recirculating these days , which makes little sense.

im running a jeboa 20000 lph their biggest pump, its quiet, not sure how the impeller block is made, it has decent flow, but it wont handle head pressure on my quad beckett , it will push 2 becketts pretty good though. Iwaki wil push all 4.

 

[CayeCaulker]

I no longer have the HSA skimmers. they sure did a good job. I had a anemone the size of a basketball spawn and they handled it no problem. I thought the needle wheel recirculating skimmers were pretty good/