NB: Please note with regards to large bore plumbing, this is just an overview page.

 For a full Hints and Tips, there will shortly be added a full section in  DIY

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Firstly an overview of the two main areas of the plumbing.

1: The main circulation system (closed loops) comprising of 4 x Sequence 10,000lph  marine grade pumps.

2: The sump, return, and overflow.

So starting off with the circulation. There were three main areas of oceanic current I wanted to recreate in this system. The first being wave roll, (to recreate the 'circular' particle motion found in waves). using the 4 bottom front outlets. And secondly, 'tidal phases', and 'longshore drift' using the other 4 side outlets.

Wave action.

In this image, (as though looking, through the left hand end of the tank) you can see the 4x 40mm  bottom front returns, blowing water upwards at 45 degrees towards the water surface 24" above. This flow is then deflected by the water surface towards the back and then down again causing a rolling motion of water across the entire reef structure, similar to what you would find with waves passing across the reef. Remember though that I'm not trying to replicate the aggressive surge that you would find right at the top of the reef crest (sub 3m). This is more a replication of the wave effect (circular particle motion) found some distance away from these areas and at a greater depth (3-20m range) so the effect is much more more dispersed with less of a  fast pulsing 'surge' and more of a constant rolling effect with small periods of either high activity or low dependant on the cycles of the pumps.. the outlets shown above are linked to 2 x sequence 10,000lph pumps. with the two nearest outlets connected to pump 1, and the two farthest connected to pump 2.

'Tidal' and 'longshore' drift.

In this instance, I have used again twin 40mm outlets at each end of the tank, situated near the surface to simulate tidal phase flow patterns. In the diagram above, you will notice two  sets of arrows. By running both 'A' outlets, a clockwise rotational flow is created which simulates the laminar flow characteristics of both tidal and oceanic current. Note these flows are not too harsh, they are simply designed to simulate the 'gentle' ongoing flow along the front of the reef, which run perpendicular to the wave action.  Outlets 'B' will run to create a 180deg shift in this rotation. This gives the full scope of tidal phases encountered where large volumes of water travel  across the reef during incoming tidal phases and the same effect, but opposite, during tide out phases. The outlets shown are connected to 2 more sequence 10,000lph closed loop pumps, with outlets 'A' connected to pump 3, and outlets 'B' connected to pump 4.

Pump timings:

Initially I had considered a wave module or computer to simulate the various flow requirements, but on further consideration I hit upon the idea of using plain simple segment plug timers for the two wave simulation pumps, and two more accurate digital timers for the tidal simulation pumps. The reason I opted for cheaper segment timers on the wave simulation pumps was that these timers don't actually keep very good time compared to one another, so there is always a certain amount of drift between the two over a period of time. This actually turns out to be a very good thing, because it means that the 1hr on 15min off cycles for each pump constantly move in relation to one another creating an infinitely variable range of on/off and combined on/off times. The reason for the digital timers on the tidal flow pumps, was that I needed these timers to be more accurate, and to stay 'in tune' with one another. As such, each pump was set to run for 6 hours on, 6 hours off, at opposing times to create that cycling motion of water that switches direction on a 6 hour cycle. There was a slight overlap  of approximately 10 min on one cycle deliberately set into the timers, to create a short period of chaotic flow that stirs up the tank a bit more than usual in an effort to free up any settling waste in areas that might escape the rest of the flow patterns. At the time of writing this section, this system has been in operation for several months with all corals and fish showing good results and behaviour in the flow patterns created, and no build-up of detritus in any areas. In fact the fish absolutely love the strong but dispersed flow patterns, and behave much like they would out on the real reef.

The timers are run on separate circuits, each linked to its own RCB, this means that in the event of a pump failing or tripping that circuit, the system doesn't suffer a catastrophic loss of flow, and at least 3 remaining pumps keep functioning.

The shots below show the underside of the set up, comprising the 4 closed loops. which all exit or enter the tank via bulkhead fittings that are silicone'd through drilled holes in either the base or sides. (note I say 'silicone'd). In the case of marine systems, bulkheads should have the perishable rubber and plastic seals removed 'prior' to assembly, and simply be sealed with a thick bead of silicone on the flange and locknut faces. After that, simply screw the lock nut up 'hand tight', and wipe off the surplus silicone that has squeezed out. 'hand tight' is crucial, if you are using a double base as the panels should never be 'pinched' by over tightening.

Notice from these shots, that each closed loop has a Tap on 'both' the inlet (nearest you in the picture which run up to the basket strainers) and outlet side (farthest away running up to the various outlets in the tank). This is crucial, as it allows you to remove a pump for servicing without having to drain the system, or at the very least, plug the bulkheads inside the tank which will disturb the inhabitants..

In the two shots above you see the completed assembly. shot 1 shows how  the 4 front outlets are teed together, to form two 'pairs' of outlets, each fed by a separate pump. The pipe coming in from the right, is the main pipe that runs up the outside of the end of the tank to the two top outlets  that create tidal flow. The shot on the right, shows all 4 pumps connected and in position. In effect (from left to right) we have when viewed from the back of the tank;

 Pump 1:  Feeds Left hand top outlets for tidal flow.

Pump 2: Feeds bottom left hand pair of outlets for wave simulation.

Pump 3: Feeds bottom right  hand pair of outlets for wave simulation.

 Pump 4:  Feeds Right hand top outlets for tidal flow.

Please Note a very important factor in the plumbing of these closed loops:  All the pumps have a nice long run of strait pipe both into and out of them before any bends or taps. This maximises flow, and limits both back pressure and cavitations caused by having these things too close to the inlets/outlets. This shouldn't be taken lightly in my experience as it will result not only in noisy pumps, but also ones that fail regularly, or at the very least, require new seal assemblies on a regular basis. likewise, there is no restriction on the pump. Inlets are all 50mm diameter from bulkhead to pump. Outlets are all 40mm from pump to tank regardless of the fact they split into two outlet points. Even under this arrangement, there is more than enough flow as you'll see later.

Additionally to this, each pump was matched in relation to the measurements between inlet and outlet taps. This enables me to switch pumps round if needs be, such as in the event of a pump failure or other problem.

After the main plumbing was assembled, it was time to move onto the rest of the system. namely the overflows, returns and main return pump manifold that is used as a splitter to feed various bits of equipment as well as return water to the tank..

Continue to the next page for further details.