One for Corona I guess

Corona - I have to move my pool pump room! Not the end of the world as I shall just cut into existing pipes where I can, but the less work to do the better - do I need a ‘bonde’ pipe into the pump or not?

During filtration, I have the skimmer tap full on and the bottom ‘bonde’ open a smigeon, but is it necessary to filter from the bottom?

Much comment on t’internet on the subject, but with many saying the modern installation does not need a bottom feed. Just as many though say yes, it is necessary :grinning:

OK, if I ever need to drain the pool, it is handy, but I have a couple of sump pumps that can do the same job… what say you (or anyone else in the know)?

Hi Adam1,
Writing @ then corna will flag him and message him directly.

Hi Adam, IMO no, you dont need a bonde. Any use of the bonde is reducing the skimming action and as dirt enters from the surface thats the best place to remove it. When I am installing if the customer wants a bonde then I offer them the option of also plumbing it as an inlet, this can be handy if its a heated pool or if the original installers only fit 1 return per skimmer.

By ‘inlet’, you mean as a return. I like your way of thinking as it will help agitate the water in general. Thanks!

As the bonde is on the same face as the skimmers, There is no danger of the water going straight up into the skimmers, reducing the effectiveness of the two returns at the other end pushing surface dirt to the skimmers?

Depending on the fitting you could fit a directional end and have it force water to the bottom and cause a rolling action to the water?
Really need to see a picture.

I have all the pipes re-routed ready to connect up and have brought the previous ‘bonde’ pipe into the return pipe but with a tap that I can regulate the supply so that it does not become too dominant. Again, I think a good suggestion. I wish this were several years ago when I woud have adopted your idea of returns and skimmers on the side walls…

Another question please - I remember some moons ago, I bought a small Vulcan UV lamp on a whim and never installed it. It is pretty small, so not sure if it will do much, but as I have it I will put it on the wall. My question is: should it go before or after the SWG…? OR, is it going to be a complete waste of time to bring it into play…?

The absolute minimum wattage for a UV system would be 55w so anything less would be a waste of time and TBH 110w is really about the min.
It would need to be plumbed before the chlorinator as UV destroys chlorine so after the chlorinator it would be counter productive. With UV and Ozone its all about the contact time so commercial units slow the water to allow several minutes of contact time with the light.

Thanks. Glad I asked!

Yes, it is 55W.

An idea I just had! How about using the bonde return as a dedicated run for an air pump, or as a conduit for an air brick??

For raising the pH?

Yep. Something you advocated once and it stuck! Presently, I have the return jets pointing upwards. Do not know if it works, other than I have few issues with TA and/or PH…

I am thinking something like this. They also do a larger one. Feed the delivery tube down the bonde pipe should do the trick, yes?

Only if its generating bubles. Lots of fine bubbles are better than a few large ones. The little pond air pump you show would take an age to do much, there are larger ones available.
With the air assisted backwash I mentioned before, I can leave the air pump on whilst in filtration and put lots of bubbles out into the water. So two great uses for the single air pump. That could use a shop vac on blow or a spa air blower.

Alternatively make one of these.

Yes, this would be a good idea - maybe not as powerful though and as I thought earlier, I would use the return pipe as a conduit for the air pipe and electricity. I shall experiment and post later!

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I appreciate people who experiment as you never know where the journey could take us. When I began modifying my setup years ago and as you know the negativity that produced from some on other forums. I really expected others to read what I had done and go off and try stuff themselves but as it turned out they preferred to sit behind their keyboards and post nasty things.
Go for it Adam.

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Have you ever posted a schematic of air assisted backwash? I know you described it in another thread. Maybe, as my pipes are not connected to anything, time to build something in if it works.

I have jerry-rigged a submersible pump with an air hose attached to the outlet as you posted above, and yes, works a treat - I could use the now redundant pipe to the ‘bonde’ as a conduit for the air hose and cable, but as I thought, the pump will not fair well with a robot.

Then I went back to venturi thinking, but the problem of course is noise if I have venturis on the outlets. But trawling around, I see Mazzei makes a large fertiliser doser - could this be installed in the pump room into the main return line that feeds the three return outlets? Presses all the buttons if it can be done - discreet and no noise…what do you think?


Give it a go Adam, they sell those in my local agri irrigation suppliers but I havent personally used one as I made the air bubbler from the submersible pump as you have and once achieved the pH was stable for a few years and is was easier to repeat the process as required which will be this season. As said previously the air assisted backwash pump can be used to run and aerate in filtration mode so I will be trying that this trip.
I will send over some details as promised.

Thanks! Yes, I’d be interested in the backwash option too. I will order a Mazzei unit from Hydraliens and give it a go before the room is all connected up.

Another question: You said earlier that if I decided to use the little Vulcan UV, it should be behind the SWG as UV plays havoc with chlorine. If I do decide on this, it means than that the Vulcan will try to kill existing chlorine already in the system only to have it replaced by the SWG… is this not overworking both items? Should I maybe forget using the Vulcan full stop? It would be a pity as I see the small unit is all of 600€ and maybe hard to sell as I have neither the box or book of words…!

I am not saying you can’t or shouldn’t use the UV but they are primarily for use on indoor pools where there is no UV to oxidise chlorine byproducts of disinfection. With an outdoor pool you have the power of the sun’s UV to do similar for free. Early on in France I visited people using chlorine free pools which were hydrogen peroxide and UV. They seldom worked beyond a first few seasons as the water ages and the filters couldn’t remove that much and fine silt etc accumilated deep in their filters. Now we have Dryden Aqua’s AFM ng, variable speed pumps we are reducing the problems of old and making pools a whole lot easier and cheaper to run. The issue that I see remaining is improving backwash so we have a clean filter to continue the great job. Commercial filters (DIN) standard backwash well and are taller than domestic versions allowing filter bed expansion without the loss of media. That does take a lot of water to achieve for a relatively small amount of dirt. With air assistance the water saving is huge and the clean more thorough so another box ticked on pool energy saving and reduction of maintenance.

I shall be using AFM instead of glass when I finally clean out and move the existing filter.

I shall bolt the Vulcan to the wall, as I am sure that it is unsaleable. I need not switch it on, although last night I did read quite a well written doc on the subject of having UV and chlorine as there are many unpronounceable things that are chlorine resistant but are zapped in seconds when faced with UV… it went on to say that UV was only a menace to chlorine in the wave band 180-400 of something else unpronounceable, and even then, it does not actually kill the chlorine but separates it from the water - yes? Sounds all very peculiar to me…how can you separate something from water - either it is in the water or not in the water :rofl: