love your tank build. I'm thinking of going the same route on my new tank build with a hidden closed loop. I had a couple questions,
is the intake hidden in the rocks as well?
does the pump collect a lot of dirt and need regular cleanings?
do you find 4 outputs to be enough for flow?
any reason why you didn;t go with a DC controllable pump for the closed loop?
on another note, what is the dimensions of your corner overflow? it looks smaller than most...are you using a herbie style drain?
sorry for all the q's...but i'm loving the clean, no wires look of your tank..
thanks
Hey Slammin, I'm all about paying it forward so I'll explain the best I can. Feel free to ask as much as you like here.
is the intake hidden in the rocks as well? Yes it is. Here is a picture of the intake before I sculpted the rock over and around it. It's a manifold so that the flow is double. This way, any debris clogging the intake would be of minimal affect long term.
In this first picture you can see where I was experimenting with black pond foam. You can see the PVC here well. I didn't like the look of the foam so removed it and ordered the sculpting epoxy.
The sculpting epoxy worked like magic. The epoxy blended with the real rock just fine. I also sprinkled some coarse reef sand on the epoxy while it was curing to give it a more natural look.
This picture shows you the rock I placed over the intake manifold. This is dry rock from TBSaltwater .com. I highly recommend it if you need guaranteed great looking reef rock for your tank. I started shaping the rock using twine but that didn't work so well so I switched to rubber bands and they did the trick. Once I had a shape that covered the manifold and looked right, I just cemented the rocks together using sculpting epoxy designed for marine use.
Polygem sculpting epoxy 307 part A & B is the secret to success with this recipe. Polygem also recommended a part C thickener agent for an extra $20. I would skip the part C thicker agent if I were to do this again because it really didn't change the consistency much they way I used it to sculpt the rock this way. I still have 2/3rds of the A & B to this day. I use small amounts of it to mount coral frags to the live rock. It really works well and goes a long way.
Here you can see the plumbing before it was disguised in the rock work. I had already drilled a hole in a real piece of rock before I bought the epoxy but in hindsight, that was a lot of work and it was much easier to encase the remaining three returns and the intake buy just putting small pieces of rock together with rubber bands and filling in the spaces with sculpting epoxy.
does the pump collect a lot of dirt and need regular cleanings? Huh? this question threw me at first. This closed loop doesn't collect any dirt and I never need to clean it. I see fish food getting sucked into the intake and shot right back out of the returns but that is happening at a rate of 2600 gph and there isn't any dirt issue or sand issue.
Now, in thinking back to when I was just adding water and sand to the tank for the first time, I do recall that I accidently poured sand right onto the intake area because the water was cloudy and I didn't think about that. The Oceans motions unit underneath has true union valves so I just removed it the one time to clean out some sand that got caught in the barrel. I could hear the sand inside the unit when that happened.
I use large grain reef sand in the tank and that keeps any sand from floating up high enough to get caught in the intake. I'd say the intake manifold is a good 4 or 5 inches above the sand bottom where the strainers start. 6-7 inches to the top of the manifold.
do you find 4 outputs to be enough for flow? Yes, 4 outputs provide so much flow you wouldn't believe it. The key is to have the gph you need to make waves. Closed loops are very efficient because gravity is pushing several pounds of water down the intake manifold all the time and that doesn't occur to more people. My pump pushes 2600 gph, has zero head loss since its a closed loop, and only uses 100 watts of electricity.
I wouldn't put more holes in the bottom of the tank if I wanted more outputs but I thought about splitting each of the 4 outputs with a Y splitter to create 8 outputs going all over the place. I guess that would be cool since the flow out of each would be reduced in half.
One thing I regret is that I elected not to install adjustable nozzles. I have been able to work around that issue by using a little sculping epoxy to shape one of the returns the way I want it. If I was going to build another tank, I'd install the nozzles but make them recess into the rock structure a bit to hide them the best I can while still being able to adjust them if needed.
The reeflo pump I have is a hybrid and it comes with a larger 3400 gph impeller. I'm only using the smaller 2600 gph impeller now and I have to dial back one of the returns slightly using a valve because otherwise the waves get big and cause some minor splashing around the edges of the tank which creates salt creep.
any reason why you didn;t go with a DC controllable pump for the closed loop? It was just because of timing. I bought the wavemaker and reeflo pump over a year ago and they were the first purchases I made for this project. The DC pumps started coming out a few months later. I've since upgraded the pump that runs in the sump to a DC pump.
You could make an inexpensive wavemaker using simple plumbing and a couple of DC pumps running on a controller or 2 timers. That would eliminate the need to buy a $450+ oceans motions wavemaker or the new german competitor version of the same. I have thought about this idea for a reefing buddies new tank because I think it would work great.
on another note, what is the dimensions of your corner overflow? it looks smaller than most...are you using a herbie style drain? The overflow is s 5x7" and that's Reef Savvy's usual return size for their 90 gallon 48"x24"x19" tank. This tank has more length and width at 50x28", plus its a little shallower at 18" so the return looks smaller but it's plenty big enough. I actually wated smaller but reef savvy advised against that and they were right.
I don't really know what defines a herbie style drain but mine has two 1" bulkheads in the bottom and water flows out of both of them. One just has a strainer connected to the bulkhead (all schedule 80 - recommended) and there is a valve to control the flow at around 90 percent. The other 10 percent of flow goes into the second bulkhead and there is a durso pipe installed on that one.
Water returns from the sump to the display tank via a 1" PVC pipe that connects into the closed loop just before the reefflo pump intake. To keep water from pouring out of the tank when the power is turned off, I ran the plumbing up above the water level of the display tank and then let gravity do its thing.
In the picture below, you can see that water travels up a 1" pvc pipe of the left. It goes past a true union valve, turns 09 degrees, and then connects to a 2" piece of PVC. Water falls a few inches since this is a height that is higher than the water level in the display tank. Gravity feeds the water back into the system and a relatively slow rate of about 500 gallons per hour. This way when the power goes out, the water in the display tank has to travel up in order to go anywhere.
There is a fish feeder you can see that dumps food 4 times a day. I really like that gadget because its no big deal if I miss a manual feeding of Mysis once in a while this way. When fish flakes are dropped into the 2" PVC, they quickly make their way into the closed loop and come flying out of the 4 returns all over the place. The fish go crazy going after the food and you don't have to worry about uneaten flakes being skimmed off the waters surface into the overflow and down to the sump.
sorry for all the q's...but i'm loving the clean, no wires look of your tank.. Thanks and I'm glad you like the setup. I work out of my home mostly and this tank is in my office so I get the pleasure of being able to look at it when on long conference calls.
I picked up all of these ideas from others here on RC so I'm no inventor. I just try to refine a little along the way and in that sense, I'm just paying it forward. Good luck to you with your own build and share your build thread link when you get it going so we can see how it turns out. Happy reefing!
