Swiftech call it the MCP655 and it has an impressive 1200 litres per hour maximum flow rate. At £52 this popular pump, used in several systems, is right on the budget.

The high flow rate deterred me at first as I concluded it could possibly overwhelm my system, and at max it’s rather noisy too.

The reason I changed my mind is it uniquely features a control dial to select the rpm so instead of running it at max chat of 4800 rpm and 1200 litres per hour I could easily dial in 1800 rpm and receive just 450 litres per hour or choose something in-between.

I tried it and although an ugly beast it is quite silent at 1800rpm, though much higher soon becomes audible. I guess it would be ideal though within a case. The seven sixteenths of an inch connections are a problem but not insurmountably so.

It’s certainly a lot of pump for the money with great performance.
    
Suffice to say I could trot out several more examples all with various strengths and weaknesses, but honestly it’s of limited value to do so because every system has different particular criteria you’ll want to satisfy or improve. I was quite staggered myself by the choice available and really every budget and level of performance is well catered for.

The whole water-cooling business is a vibrant and thriving arena with many bargains to be had, particularly online, so take the plunge - you may be pleasantly surprised.

Anyway cutting to the chase I eventually chose this one from Eheim.

Here’s how it came, just out of the box. The turquoise thing in a bag is a sponge filter, for use when submerging the pump in a pond for example, to stop foreign objects fouling the impeller. Not required for my purpose.

Eheim of Germany has been making pumps since 1949 and supply many professional enterprises like zoos, laboratories and medical facilities, with quiet and reliable pumps. This heritage is reassuring because essentially I’m entrusting some valuable assets to their care and once fitted I’d really like to confidently forget about pumps for a while.

It’s a company with over forty international distributors and bags of kudos with the tropical fish fraternity, so sounds to me I’ll be able to do just that.  
 
Thanks to Aquatics-online.co.uk who supplied me quickly and cheaply. At £37.98 including VAT and shipping, their value is hard to beat and came at a welcome saving on the budget.

Next, how does this one work?