DIY 6

In this section I'm going to run through the building of those sections mentioned on the previous page. Although the specifics of certain systems may require you to alter these plans, the general methods involved will stay the same. I will start off with the main plumbing i.e. overflows and returns, and then progress onto the closed loops.

As a pre curser, here is a quick reminder of the full plumbing set up. There have been certain alterations to this design over time, with the addition of a fifth closed loop and the re-placement of the two closed loop pumps that were originally going to sit on the top braces at the back corners. I have now shifted all pumps down into the cabinet for neatness and simplicity. At this moment in time though I'm pondering over replacing 4 of the Aquabee 3000's with two Ocean Runner 6500's. This wont make any major difference to the overall plumbing layout. All it will involve is the teeing of two of the closed loop returns into each outlet of the bigger Ocean Runners, and likewise with the input end. In this case I may review the 5 central take offs, and swap them for two 32mm take offs instead.

The pumps shown above make up the various links in the system comprising of. 'A' skimmer feed pump taken from the first sump compartment. 'B' the 5 closed loop pumps with the intakes running down from the top centre of the tank via a strainer box. These then run out from the pumps and back up to the various outlets of the 5 loops. 'C' These are the two return pumps for the sump which can be switched independently depending on the turnover required. Obviously there will be subtle differences if I do go down the twin OR6500 route, but as I said before, these will be minimal simply involving teeing a few of the pipes together to form single connectors to the pumps. The brown pipes represent the overflow pipes coming from the weirs as shown in my DIY section via a 90deg bulkhead fitting, one of which is teed off to the raised DSB..

In an effort to ensure adequate flow of water back to the sump it was important that I used a pipe and bulkhead fitting with a diameter that would easily cope with the amount of water coming back up from the pumps. I decided prior to ordering the tank that I wanted two overflows for safety reasons i.e. blockages, and to evenly draw water/waste from both ends of the tank. So the tank was ordered with two 55mm holes which would give me scope for various sized bulkhead fittings. In the end I opted for 40mm 'Marley' push fit waste pipe, coupled up to a bulkhead fitting that would take water from the overflow weirs and strait down to the sump. I had to take certain factors into consideration, such as 'Teeing off' the DSB feed from one of them. So in the end I decided that the pipe on the right hand side of the tank (when viewed from the rear) would be the split overflow/DSB feed. Whilst the LHS pipe would run strait to the sump and compartment 1 where the skimmer take off is situated. Both these sections were constructed using 'push fit' piping, so it was important to support any horizontal sections 'I.e. those that run along the top of the sump' to prevent the possibility of the joints being pushed apart with the force of water hurtling down from the tank and then hitting the first bend.

In the photo's below you can see how, by using several 45deg bends I have brought the pipe down, into the sump bay, and then along the side of the sump tank. From this a Tee junction is inserted onto which a further 90deg bend is added to divert flow down into the DSB. On the end of this pipe is a strait link with an end cap inserted to prevent masses of bubbles making a pest of themselves. Holes are drilled into the strait pipe above the coupling to allow water and detritus to flow 'across' the DSB rather than strait down onto the sand surface which would cause disturbance of the sand layers. This type of drilled end, also means that food or detritus is evenly distributed over the entire bed, and not just one section. The ends that sit in the first sump compartment spend their time submerged. This is to reduce noise and bubbles when water flows out. (pic 2) . To increase or decrease the amount of flow that enters the DSB, the tee junction is simply tilted on its seal, (pic 1 'A') 'down' = more flow to the sand bed and less to the sump, or 'up' = less flow to the sand bed, and more to the sump. Any surplus water flows past the tee, and strait out the end into sump compartment 1. By tilting the Tee strait up, it lifts the DSB feed pipe out and up, which cuts off flow to the DSB area completely, should I need to do any work on the bed itself. Or to salvage/protect either the tank or DSB in the event of a catastrophe, whilst still being able to utilise the rest of the sump.

The following pictures show the various closed loops and how they were laid out inside the tank. I felt that this layout gave the best look i.e. neatness, whilst at the same time keeping pipe lengths to respectable levels in the interests of friction loss. Once the tank was running, the only visible piping was the two corner outlets and the bottom of the outflow box. Just the nozzles were visible on the front sand bed loop. If I was to do it again I would be very tempted to drill several holes in the top of the back panel and pass each pipe through via bulkhead fitting rather than over the top. although there is the added risk of stressing the panel when dealing with multiple holes, so its a personal choice really.

For the returns, certain aspects had to be kept in mind. Specifically what happens if and when the pumps go off. In systems that utilise drilled rear panels for overflows and returns, this should always be accounted for. By and large, an overflow weir does not concern us, as the top edge of the weir itself creates and sets the water level in the tank. The problems arise when we are feeding or taking water from anywhere below the surface be it from over the back panel or through it. Since the level of the return nozzles is below that of the water level in the tank, there would have been the danger that when the pumps go off, a large amount of water would back siphon into to sump from the tank itself, in this case about 35gallons (or the top 6" of water that sits above these nozzles in the tank) which is way over the spare space left in the sump when at its normal running level, so it would have meant a flood. To get round this, a simple anti-siphon setup is installed utilising an up-turned 'U' bend.

As can be seen from the picture. Water flows from the return pump up to the bend assembly and then back down to the outlet nozzle which is situated through the drilled hole in the tanks back panel via a bulkhead fitting. At the top of this bend I have drilled a small hole into which a small bore solid pipe (5mm external/3mm internal) is sealed. this pipe runs strait out from the top of this section, and over the top lip of the tank, ending with a bend that runs down to sit just clear of the water surface as set by the overflow weirs. When the return pumps are running water is pushed up the main pipe and out through the nozzle, however a small amount of water is also forced along the small pipe to exit into the tank as well.

In the event of the pumps being switched off, or the power failing. Air is drawn into the small pipe by the suction/siphon effect of water falling back down the main pipe to the sump. this fills the top of the bend assembly with air and the siphon is broken. The only water to make it back to the sump is the volume of water that was originally held in the pipe. When the pumps come back on, the whole assembly fills again as before.

Although there is some extra head pressure created by forcing the water up higher than would normally be required (i.e. about 4" above the water surface in the main tank). this is counteracted by the drop back down to the nozzle. In effect the only additional work the pump has to do, is moving water round the two 90deg bends.

(Note: Many thanks to Ed Miller AKA 'Dragon' on at Ultimatereef.com for this idea,, cheers Ed)

Since every set up will vary slightly I have refrained from going into too much detail on each section i.e. lengths etc.. But here are a few hints and tips I've picked up on the way which should help you if you wish to have a go at your own piping.

1. Make sure that the cut ends on each pipe are square. There are proper pipe cutters on the market however a saw will suffice if your careful, and take your time. After each piece has been cut, the ends will need de-burring and smoothing. Running a Stanley knife round the inside of the end will do this quite nicely.

2. Make sure that the ends of the piping are clean and grease free prior to bonding to avoid leaks, or weak joints that will blow under pressure. Likewise blow through each pipe to get rid of any 'swarf' that has collected on the inside from the cutting process.

3. The glue used in solvent weld pipe, is very fast acting i.e. 5-10 sec until the joint becomes unmoveable. Baring this in mind, I would strongly advise that you make each section/loop, up fully in a loose fit fashion prior to welding. This will save you allot of money 'and joints' later on, as once a joint has been bonded it is impossible to break.

4. Once you are happy that everything fits together ok and lines up nice and neat you can start to weld up each piece in turn. Start at one end and work your way along in order.

5. When bonding sections that have multiple couplings etc or a piece of pipe with a 90 or 45deg bend at each end, my best advise would be to lay them on a flat/work surface as you glue them together this will ensure that joints are square to each other, and run true.

6. When applying the glue, smear a small amount round the 'inside' of the coupling face, rather than the end of the pipe that will slot inside. If glue is applied to the pipe end, it will be pushed back as the pipe is pushed into the coupling creating a weak bond. Smearing glue round the internal face of the coupling and then spinning the inserted pipe through 90deg will ensure an even coverage of glue round the joint faces and give a better seal/bond.

7. Over the course of time, it will become essential to clean your plumbing out at least once every two years if not every year due to the microbial / algal build up that occurs. Doing this is quite simple. Remove the section of tubing you wish to work on. Then pass a length of string or fishing line down it with a small weight attached that will fall along the pipe. At the other end of this, attach half a plate scourer (non toxic type) and simply pull through to the other end. 'You may have to do this a couple of times'. Running hot water down the pipe first will help loosen any stubborn build-up, although calcareous build-up can only be removed by filling the section up with a mild vinegar solution for a few hours and then flushing through thoroughly.

Important note. Once your plumbing is completed and your tank is filled. Don't forget to bleed each loop through, prior to turning on your pumps. Fitting a bleed nozzle at a high point in each loop will make this easier. (Starting pumps up dry, may severely damage them). Also, never forget to fit shut off taps on both sides of a closed loop pump, and externally mounted return pumps. this is the only way to shut them off for removal should they need maintanance.

Hopefully, this section has given you some ideas or at least a head start if you want to do your own plumbing.