# Central heating pump conversion



## Vanish (3 Apr 2013)

Firstly thanks to Fox fish, as I've copied one of his ideas of using a central heating pump to circulate water in my aquarium.  
I purchased a used grundfos pump from eBay for £5. 






I also purchased a aqua turn conversion kit also from eBay. This cost around £10. 



 
These kits are designed for aquarists and pond use, I understand that they are popular with people who keep Koi. Apparently they save the pump from corrosion of the cast iron housing that can be caused by circulating cold water. 

When I stripped the pump down I found that there was a lot of black scale obviously caused by the hard water in my area and also the sludge that is found in heating systems. 



I scraped this off and  cleaned the impeller under a tap. 



As you'll see it now looks more fit for purpose. 
And here it is fitted with the aquaturn which is held in place with four Allen bolts. 




Next I glued in place two 22mm - 15mm spigot end reducers. This is so I can attach flexible tubing, this tubing connects onto my reactor and also easily pushes onto my spray bar. 




Here's everything all connected up. 




And here's the full length spray bar which I crafted tonight.


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## martinmjr62 (4 Apr 2013)

Interesting idea,not sure that i'd use a second hand pump though knowing that some heating systems use chemicals such as fernox in them to help with the anti corrrosion and black sludge.what do you do for filtration then if not using a filter ?
Cheers
Martin


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## foxfish (4 Apr 2013)

It was maybe 25 years ago that the Aquaturn conversion was awarded the Prince Charles first prize for innovation (a big thing in those days) at the time I was working full time with aquatics & bought a trade quantity of the moldings (they were green at the time) 50 units I seem to remember
I only have one unused one left but there are still many that I installed that have been running for all those years!!
The pumps are incredibly reliable & incredibly cheap considering there robust construction, I assume this is made possible by the astronomical quantities that have been & are being produced!
The pumps run very quietly & are vibration free, however they are not the most economical to run.
The conversion units are designed to except standard household plumbing pipe (21mm overflow or 32mm waste) that simply push fit securely into the molding!
I have installed them on ponds, water features, marine tanks & freshwater tanks.


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## Vanish (4 Apr 2013)

Martin I also have. Tetratec EX1200 fitted, though the flow through this is not what I'd like it to be. I did consider fitting the pump to the filter inlet to push water through at a quicker rate. You mention the inhibitor used in CH systems, all of the muck basically flaked off, the rest cleaned off with a brush under the tap. 

Foxfish, wow 25 years and still going strong. I do love the pump , I have mine on setting 3 which by my calculations at a 1.5 meter head is around 3000lph. So I've finally got to have a 10x tank circulation. And as you say it is silent, all that I can hear is the water running into the reactor. I could do with fitting a lift pump to prime the circulation pump. Any ideas?


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## foxfish (4 Apr 2013)

Not sure i would need to see a picture or diagram.....
　
TYPE OF PUMP					SPEED	   POWER	  LITRES PH	 LITRES PH	   LITRES PH
																					  ZERO			 1 METRE		  2 METRE
KIT																				  HEAD			 HEAD				HEAD
15/50 & 15/60							3				  90			  4100			   3200				  1900
Grundfos Pump						  2				 65			   2500			   1500				   900
												   1				 40			   1300				700				   150


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## Vanish (4 Apr 2013)

Mine is a 15/50. I'm looking for something to lift the water from the aquarium into the pump to prime it. I've had a search but can't find anything other than fuel lift pumps.


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## foxfish (4 Apr 2013)

Sorry about my last post, It was meant to be a graph of the pumps performance but the forum rearranged it!
It is unusual to have a pump above the tank but any submersible pump (powerhead) will lift water.


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## Vanish (4 Apr 2013)

I guess I'm trying to over complicate things, which is not unusual for me. Anyway I'm happy with how it all works, but time will tell if I have got the distribution correct.


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## idris (17 Apr 2013)

Thanks for posting this Vanish (I don't seem to have had email alerts from the forum recently so hadn't seen your pointer to it in the other thread.)

Where did you get the reducers from and how did you glue them in? (I'm guessing silicon or plastic-weld.)


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## Vanish (17 Apr 2013)

Reducers are from b&q but you'll find them at any plumb stockist. Glue is solvent cement, but not really needed as the fittings push in really tight. I'm going to remove mine and fit 22mm tube, this just pushes into the aqua turn in/outlet. The reason is the 15mm reduces flow too much. Then I'll make a spray bar from 25mm black electrical tube/duct as suggested in another thread by Foxfish. He obviously has a lot of experience with this kind of stuff as he's got some good ideas.


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## idris (17 Apr 2013)

Do I understand right that you're fitting flexible hose INTO the pump outlets, rather than the pump outlet fitting into the hose?


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## Vanish (17 Apr 2013)

I will be using some rigid tube. Although I need to give more consideration to the exact design yet.


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## idris (17 Apr 2013)

I see. I'd probably use hose, but the outlets look a bit shorter than I'd really be comfortable for that. Maybe some more thought for me too. Ha ha.


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## foxfish (18 Apr 2013)

The conversion are designed to accept standard overflow pipe as a push in fit, the aqua turn is made from polythene & will not accept glue like pvc pipe does.
I have never had an issue with the 'push fit' fitting however I did use a stainless screw through the side once, because I was a bit paranoid about the pressure but all that happened was the screw corroded after a few years (yes stainless steel) and a leak formed!
So yes the the pipe fits inside the 21.5mm hole designed to take white pvc overflow pipe.


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## idris (18 Apr 2013)

Can you safely fit hose over the outlet/inlet? They Look a bit too short to confidently treat as hose-tails. 
Obviously I could fit a short length of overflow pipe and then attach hose to that, but it would be nice to not have to.


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## foxfish (18 Apr 2013)

Personally I would not even consider doing that! Why do you want to use such big diameter hose anyway?
Virtually all external filters use 16mm pipe, this is already 21mm and capable of carrying 4500lph.
If you want to use flexy pipe then you should do as you suggested & insert the proper overflow pipe which cost about £3 for 3 meters from any DIY, B&Q or plumbing outlet, then jubilee clip on the flexy.


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## dean (23 Apr 2013)

Can't seem to find any conversion kits listed on eBay


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## foxfish (23 Apr 2013)

Aqua-Turn conversion kit for Grundfos Pumps Koi Ponds and Filter LARGE and small | eBay
They are called Aqaturn


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## Edvet (8 Oct 2015)

I could only find two listing  on Ebay the last months, probably people who had the original conversion set still unused.


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