Plumbing

Plumbing your water feature can be the easiest or worst part of construction and maintenance. This article attempts to avoid the two most common plumbing pitfalls, under planning and poor construction.

Planning:
First, in any design,planning should be given the utmost attention to achieve the desired results. That is, what will the final effect be? Quantity and quality of sights, sounds and utility can be achieved only with adequate planning. Plumbing is frequently a sore area in this regard. In designing your water feature give thought to the following plumbing lines:

• I) Intake(s)
• 2) Discharge(s)
• 3) Filter and Pump
• 4) Drain(s)
• 5) Overflow
• 6) Fill line

Materials:
Thank goodness this is the nineties! Hurrah for plastic pipe! Most of the plumbing you will do on your water feature may be done with PVC (poly vinyl chloride) pipe. I suggest schedule forty for adequate strength and thickness. Hot on the scene is the use of flexible pvc pipe that may be joined to the rigid type with a special solvent. Pipe and fittings are readily available and easy to use.Cutting tools are available for low cost or rental except for the standby hacksaw or friction-string trick. Ask your dealer about solvents that are appropriate for use. There are many that require no primer and work well under less than ideal conditions around dirt and moisture.

Pipe Size: Commonly pipelines are undersized and only occasionally oversized. As a rule of thumb, never use pipe smaller than the intake or discharge of the pump. Among other ills, this practice will reduce flow and motor life and increase energy costs. In other words, don't do it! Overflow and drain lines should be way oversized. Anything smaller than 1½" is a bad joke especially if there is a long run with any number of turns.

Valves:
Valves should be:

• I) Schedule 40
• 2) Plastic
• 3) Ball type

Layout:
It is understood that the best layout is the least complicated and conspicuous. If possible, plumbing entering the water holding basin(s)should he installed to eliminate any leak potential. This is especially true in concreted basins, particularly ones using a liner as a water impermeable membrane. Their plumbing may be installed down over the membrane or attached to the wire reinforcing mesh and covered by concrete. These lines may enter and exit the basin above the water line. If the plumbing is to be fitted through the basin below water level, care must be taken to prevent leaking. See the construction articles in this series. Plumbing should be buried at sufficient depth to prevent breakage. See the excavation article for checking local codes for guidelines.

Intakes:
Intake lines to pump(s) or other units should be as many and large of size as practical. For biological ponds, the intakes should be situated just off the bottom. So called bad water should be left below where it may be vented to waste via the drain line. If the intake is plumbed to the pond bottom then a settling basin should be installed between the pond and filtration system.

Pump And Filter Lines:
The size of intake line(s) to the pump may be reduced or bushed to the size of the intake right at the pump. As noted in the article concerning pumps, most are made to push, not pull. So care should be taken in designing and building the plumbing lines to reduce restriction on the intake side as much as possible. If the pump system is above water level, check valves and/or ball valves should be installed right before and after the pump. If the pump system is below water level, union ball valves will allow you to clean out your trap or make pump repair/removal with minimal water loss or flooding. While providing plumbing to the pump and filter, there arises a possibility of providing a vac-line. The specialty plumbing is appropriate in cases where there is inadequate self cleaning by design. Either through a pool designed skimmer system in the basin, two, two-way or one, three-way valve system with a hook up for a periodic vacuuming. This vac system is something you may want to provide for initially in design and installing the plumbing.

Discharge:
These lines should be as short as possible. There is generally not much to be gained by sizing up the discharge(s) beyond that of the size of the pump. Much pump efficiency is lost through extra turns and added length of pipe. Plan and measure twice, cut and glue once. Discharges should be non restricted at their ends. If possible, a discharge end should he left completely open. You may want an alternate discharge to vent water for irrigation, drainage or to dump the system.

Drains:
You will thank me and yourself later for installing a drain line or at least a definitely deeper area, possibly with a sump. A drain and/or sump will greatly simplfy cleaning, partial water change and dumping. We have found it expedient to pre insert a drainage box (conduit) or in very small systems pour concrete and install a bucket with rocks to leave a depression in the deepest part when the bucket is removed. The concrete mix is troweled around this area to provide a fairly steep slope to direct the debris into the cavity. If possible, use gravity to drain the feature. situating a ball valve for control in the most convenient, accessible area. Take care that this waste water goes where you want it to go and will do the least harm. It is often appropriate to connect the overflow line with the drain line and run them collectively to waste,saving cost and flushing. The simplest overflow is the lowest edge of the system. You might want to intentionally construct this area and provide it with a screen to keep livestock in and debris out. As previously stated, imagine a flood of biblical proportions when sizing your pipe - the bigger the better.

Fill Line:
All systems will benefit by an automatic refill or continuous drip make up system. You can provide one of these by tapping off a pressurized irrigation line or potable water line. There are a wide range of available types and costs, from simple mechanical ''toilet ball'' floats, to sophisticated electronic sensors and solenoid devices.

Conclusion:
It may seem from this discussion that you are going to have to become an engineer and plumber to build your water feature. Such is not so with new tools and materials and with ourselves and others for help.By following the advice presented here and in this series you will be able to plan properly, construct and maintain your feature with a minimum of hassle. Check Valves (or, I wish I had all the money in burnt out and flooded pumps... When using an emersed versus a submersed pump on a water feature there is a field of technology everyone should be familiar with--the use of check valves in plumbing. Check valves or one way valves are devices that hold water static in plumbing when the pump(s) are off. The lack of appropriate use of these valve's is the cause of much time loss and frustration in re-priming lines and replacing plumbing and flooded equipment. By judicious use of check valves a would-be waterscaper can keep his/her sanity by keeping the plumbing lines primed, i.e., full of water. Without check valves all manner of havoc is manifested by loss of prime, motors, pumps and more personal items like tearing of hair! So what are these magical devices, how do they work and when and where do you use them? Check valves help you keep your cool.

What:
Check valves are specialized fittings that, attached in line with your plumbing, actuate when the water stops flowing and prevent the water from back-flowing. Most often used and available are: Swing, spring and ball types.

How:
Swing, spring and ball type check valves function the same. The force of moving water unseats the check allowing flow through the valve. When flow stops, the weight of water (or in the spring check, with the additional ''push'' of the spring) closes the valve.

When And When:
So what's the big deal, you ask? Hah! How many of us have sucked on, put hoses in, swore at, begged. cried and prayed that our pump and drain lines would work and all for naught because you couldn't get enough liquid in them? Well, check valves can change all that! As explained in a previous article in this series, there are two possible spatial arrangements for a pump that is not underwater. These are above and below the water level of the lowest basin. In either case, the desire is to have the ability to clean the pump trap or filter, and do repair or removal of the pump and filter system without the loss of prime or flooding. If your water feature's pump and filter system is below water level, you will want to have a shut-off valve before the pump to stop water flow while you are working on the system. Similarly, you will want to provide a shut-off or check valve immediately after pump and filter to prevent the line from back siphoning and thereby dewatering the upper basin and discharge line. A shut-off valve may be used on the discharge line rather than a check valve, but these are more expensive and flow restricting. In the second scenario where the pump/filter system is above water level, two check valves may be used instead of one check, and one shut-off. These will be cut in as per the previous illustration.

Choice:
Now my views regarding what types of check valves are best per given application. Most commonly available are brass and PVC bodied check valves. The PVC are more appropriate for systems with less than three inch plumbing. This is especially true with lower flow rate and low pump heads with PVC lines. For systems with fish or plants in them, swing-type, checks are the overwhelming favorites.. Various flotsam and jetsam will usually not clog a swing check as readily, are cheaper and have a longer service life. For biological and "poisoned'' systems with no life in them, a more preferred type may be low tension spring checks. These are especially useful in a low head situation where there is little difference between the highest and lowest water 1evels. With the added force of the spring, a positive seal is assured. What may be otherwise lost is some pressure and volume compared to a swing-type check valve.

Shut-off Valves:
As per our previous article, the best available,most appropriate technology in valves is plastic (usually PVC), schedule forty or rarely eighty, ball valves. True union valves that will allow easy removal of parts without cutting are strongly suggested.

Note:
With a submersed pump, you may still want to install a check valve on the discharge line to prevent back siphoning if the discharge point is below water level, Also Note: Many people believe their pumps are self priming or, "it will start after awhile,'' running dry. This belief is a dangerous notion. Do not run your pump dry. Running dry hurts the life of the motor, ruins the pump and can be extremely dangerous. If you discover your pump has been running without water in it, turn it off to allow it to cool down. Discover the cause(s) of the problem. Cure the problem, re-prime the lines and then turn the pump back on.