Pumps, pipes, uv's and Pond bio filters and how to use them

There is a relationship between these components in a pond system and it can be a little confusing as to what goes where and what size is required.

The first thing to bear in mind is the wrongly sized pump or uv or pond filter or even the pipe can create significant problems or I should say hassles for you. The pump is normally placed in the pond itself. Do not place it right at the bottom. It is a good idea to place it on a brick so that the "muck" sucked into the pump is minimized. You will have to remove the pump at times to clean it .... this can be every 2 days or so in hot weather if the pump has a foam strainer (it will get blocked with slimy algae deposits). So make sure you can get it out of the pond without pulling it by the cable.

Many pumps have a handle ... tie some strong transparent fishing line to this handle if you have deep water so you can pull the pump up using this and not the cable.

Select the widest diameter pipe you can easily fix to the pump and place the pump so that the length of pipe is short ... in a small pond circulation is not helped to any significant effect by placing the pump at the opposite end from the waterfall as some would say.

I mentioned this before ... Do not use transparent plastic pipe if you can avoid it since algae grows well inside such pipes and can block the flow ... the picture shows the best type of pipe to use. In the worst case this could cause you to pump the whole pond dry. This would happen if the outlet pipe from the pond filter becomes restricted and you are still pumping away into the filter ..... I promise this has happened on countless occasions.

In placing a pond filter try to locate the filter such that the overflowing water will find its way naturally back into the pond if this overflow does happen.

Next in the circuit is the UV .... ie before the pond filter.

UV clarifiers are normally weather resistant but NOT waterproof to the extent you can submerge them. The main reason for the UV being before the pond filter is that they need some pressure to get the water through the UV and keep the quartz tube full of water for maximum radiation impact. If your pump is too strong for your UV or pumps too much water into your pond filter (you can tell this is the case if your pond filter tends to overflow out of the lid) beware.

You can do a couple of things to overcome the problem. You do not need to buy a new pump...

At the pump outlet install a valve with 2 outlets as in the picture. Many pumps come with this fitting as standard. Position a pipe on one outlet to the UV and another either directly back into the pond or route it to the waterfall (in fact you do not even need a second piece of pipe if you don't have a waterfall ... just leave the valve open under the water's surface.

Adjust the position of the valve(s) so you still get enough water flow to the UV and pond filter. You can reduce flow further by taking a clamp and squeeze the outlet pipe ... this will reduce the flow. If you have not got a clamp then "kink" or bend the pipe or put a heavy stone on top of the pipe. You could even tie a stout ribbon around the pipe if your pipe is flexible enough.

Instead of a valve you can use a simple 'Y' piece or even a 'T' piece. The idea is to create a restriction which will automatically reduce the flow. This will do no damage at all to your pump .... not even if the restriction completely stopped the water flow.

The ideal place to restrict the pipe is after the UV and before the pond filter but not critical.

If your UV quartz tube is not running full then you run the risk of the tube getting a film of dirt on the inside of it. This can significantly effect the algae-killing power. It is not a bad idea to occasionally check your quartz tube for cleanliness if you suspect a drop off in efficiency. If you do find your tube is dirty and scaled up use a dilute acid solution to clean the scale away.

If you have a habit of closing down the UV and by passing the water flow completely to prolong the life of the light itself be aware that the quartz tube will almost certainly become "fogged" up as solids in the water deposit onto the tube surface and harden (following water evaporation)

Now for the pond filter ... the biggest problem faced by most pond keepers is to hide the ugly box or other contraption and especially so since often the pond filter is at the highest point in the circuit .... because the outlet of water is under gravity flow conditions.

The next consideration to recognize is that the amount of water you can safely pump into a pond filter is determined by the size of the OUTLET hole in any gravity filter.

To minimise the risk of overflow do as suggested in the UV section above ... you might not have an UV of course.

Do not be scared of by-passing some water around the pond filter as some folks are. This will not have any impact upon your pond filters performance (within reason of course). This by-passing trick allows you to reposition the pond filter at some other point lower than the top of the waterfall making it possibly easier to hide with plants and the like.

By selecting highly efficient biomedia for your pond filter you can reduce the physical size of the box dramatically. This makes hiding even easier. Prevent biomedia finding its way into the outlet thereby blocking this pipe.