Hi All,

My mate with a greenhouse (well several g) showed me a small blue
metal bodied pump that us used to mix via a 'Computer' (not as we know
it) and solenoid valves, varying amounts of acid and alkali into the
alto watering mix for his 4,000 tomato plants ;-)

He showed me a sorry looking pump that he said cost 400 pounds new.

It's a 240V single phase jobby and about 140mm long by 80mm diameter
and uses an inductive coupling to drive the plastic impeller in the
plastic pump body (is that what they do in shower pumps?). From memory
the pump flow return had an inner bore of about 10mm.

I was wondering if anyone in an industry that might use such equipment
might know of what might make a 'cheap' (but reliable) replacement
maybe please?

He recently used up his last 'spare' as one (of the three in use)
seized solid. I'll be taking him some Plus Gas as he was trying WD40
on it (when will folk learn ?sigh)

All the best ..

T i m

"T i m" wrote in message
news
Hi All,

My mate with a greenhouse (well several g) showed me a small blue
metal bodied pump that us used to mix via a 'Computer' (not as we know
it) and solenoid valves, varying amounts of acid and alkali into the
alto watering mix for his 4,000 tomato plants ;-)

He showed me a sorry looking pump that he said cost 400 pounds new.

It's a 240V single phase jobby and about 140mm long by 80mm diameter
and uses an inductive coupling to drive the plastic impeller in the
plastic pump body (is that what they do in shower pumps?). From memory
the pump flow return had an inner bore of about 10mm.

I was wondering if anyone in an industry that might use such equipment
might know of what might make a 'cheap' (but reliable) replacement
maybe please?

He recently used up his last 'spare' as one (of the three in use)
seized solid. I'll be taking him some Plus Gas as he was trying WD40
on it (when will folk learn ?sigh)

All the best ..

T i m

Sounds like a magnetically coupled pump (magpump) with a sealed impellor
housing.
March May make a range of these pumps. I aven't found a web address but
this is their number - 01480) 214444 - they are in St Neots.
The most regular failure of these pumps is caused through running them dry,
this melts the seating of the impellor bearing.

"T i m" wrote in message
news
Hi All,

My mate with a greenhouse (well several g) showed me a small blue
metal bodied pump that us used to mix via a 'Computer' (not as we know
it) and solenoid valves, varying amounts of acid and alkali into the
alto watering mix for his 4,000 tomato plants ;-)

He showed me a sorry looking pump that he said cost 400 pounds new.

It's a 240V single phase jobby and about 140mm long by 80mm diameter
and uses an inductive coupling to drive the plastic impeller in the
plastic pump body (is that what they do in shower pumps?). From memory
the pump flow return had an inner bore of about 10mm.

I was wondering if anyone in an industry that might use such equipment
might know of what might make a 'cheap' (but reliable) replacement
maybe please?

He recently used up his last 'spare' as one (of the three in use)
seized solid. I'll be taking him some Plus Gas as he was trying WD40
on it (when will folk learn ?sigh)

Central heating circulators (pumps to you & me) will take all sorts of abuse
and are free for the skipdiving.

Mind you what sort of 'acid' is he feeding his 'tomato plants' ? ;-)

On Fri, 9 Apr 2004 19:13:41 +0100, "John Stumbles"
wrote:

"T i m" wrote in message
news
Hi All,

My mate with a greenhouse (well several g) showed me a small blue
metal bodied pump that us used to mix via a 'Computer' (not as we know
it) and solenoid valves, varying amounts of acid and alkali into the
alto watering mix for his 4,000 tomato plants ;-)

Central heating circulators (pumps to you & me) will take all sorts of abuse
and are free for the skipdiving.

Do they have an isolated impeller John? I'n not sure how the seals /
bearings would cope in this environment?

Mind you what sort of 'acid' is he feeding his 'tomato plants' ? ;-)

I'm not exactly sure .. other than whatever it is, it's safe enough to
put yer fingers in (apparently)?

The plants need a ph of 5.5 (or summat) and as the water is regularly
pumped round to each plant from a tank the size of a swimming pool,
it's 'mixed' (on the fly) in a small tank (the size of a domestic
water tank) with acid / alkali to try to hit the required ph.

He even buys boxes of bees in to assist with the pollenation .. 1
pound 50 per bee I believe!

All the best ..

T i m

"T i m" wrote in message
...
On Fri, 9 Apr 2004 19:13:41 +0100, "John Stumbles"
wrote:

"T i m" wrote in message
news
Hi All,

My mate with a greenhouse (well several g) showed me a small blue
metal bodied pump that us used to mix via a 'Computer' (not as we know
it) and solenoid valves, varying amounts of acid and alkali into the
alto watering mix for his 4,000 tomato plants ;-)

Central heating circulators (pumps to you & me) will take all sorts of
abuse
and are free for the skipdiving.

Do they have an isolated impeller John? I'n not sure how the seals /
bearings would cope in this environment?

The last set up I saw was under the trade name VOCOM. IIRC there were
storage tanks for about three lots of feedstock and a buffer tank which
recirculated via a pump with graduated injector valves which were located on
the suction side of the pump so as to draw the stock chemicals into the
water. I can recall pH probes, conductivity, and dissolved oxygen probes in
the control loop as well as a flow sensor in the pumped output to the
greenhouses which gave early indication to the programmable controller
handling everything. Out in the greenhouses the header pipe branched off via
solenoid valves to subsections of the crop. It was possible to give each
section a session of "watering" with appropriate nutrients for that
particular crop.
The pumps on a Vocom were Grundfos again IIRC


Mind you what sort of 'acid' is he feeding his 'tomato plants' ? ;-)

Phosphoric sticks in my mind so probably weak Coca Cola strength


I'm not exactly sure .. other than whatever it is, it's safe enough to
put yer fingers in (apparently)?

The plants need a ph of 5.5 (or summat) and as the water is regularly
pumped round to each plant from a tank the size of a swimming pool,
it's 'mixed' (on the fly) in a small tank (the size of a domestic
water tank) with acid / alkali to try to hit the required ph.

He even buys boxes of bees in to assist with the pollenation .. 1
pound 50 per bee I believe!

Cucumber growers use biological predators to control aphids and other pests
(but don't ask about the Hydroflouric acid used each year to clean the glass
or the formaldehyde sprayed about with gay abandon to clean up during the
off seasong)