abcha0s' 300G Ultimate Reef

[abcha0s]

Aquascaping is fun, but not an easy task. I’m pretty happy with what I managed in my 90g, but this tank is a little bigger. I’m also working with over 300 pounds of rock.

I really don’t want the rock sitting on the glass and buried in the sand. In my opinion, this causes a whole set of problems not the least of which is an unstable base structure. Instead, I want the rock elevated slightly above the sand. Amongst other things, this should help to ensure good flow while creating additional caves and shelter for various fish and inverts.

To accomplish this, I envisioned a peg board style base where I could plug acrylic rods wherever they were needed. If I wanted to move a rock to a different location, I could just move the pegs. Depending on the size and shape of the rock, the pegs can be inserted in a variety of combinations.

.

The rock above is supported by this peg configuration:



Assembly

There are two acrylic sheets.

The bottom layer is ¼” and does not have any holes drilled in it. The purpose of this sheet is primarily load distribution to avoid the effect of point loading.

The top layer is ½”. This layer has to be thick enough to provide adequate support for the pegs.

The pegs are ½” acrylic rod. The pegs are friction fit into the holes and are not glued in place.

The two sheets of acrylic are bonded together with Methylene Chloride. This was actually fairly easy to do. I simply used a syringe applicator to circle around the bottom of each hole and the sheets bonded together. I completed this step in the tank as I wanted a flat surface to work on to ensure the acrylic didn’t warp.

Construction

A grid was drawn. There are more holes towards the back. Spacing was 1”, 2”, 2.5”, 2.5”, 3” and repeating. The idea is that rock will be denser towards the back of the tank.



Drilling the holes was more tedious than difficult. The biggest challenge was keeping the drill straight. Not all of the holes are perfectly vertical but, other than aesthetics, I don’t see this as a problem.



That’s a lot of holes. Notice the third row at the back. I drilled these holes just for good measure.



Having put the acrylic sheets into the tank, this was my first trial.



One of the problems that I wanted to avoid was having sand get between the acrylic and the glass bottom. I cleaned everything the best that I could and then siliconed the acrylic to the glass around the edges. I know that silicone does not bond well to acrylic, but I also know from experience that it does bond well enough when there is no pressure or stress on the seam. In this application, the weight of the rock will help to keep the sheets in place and the silicone is really only to keep the sheets from sliding and sand from getting under the acrylic. I used the weights to hold the acrylic in place while I was applying the silicone to ensure that there were no gaps.



Conclusions

One obvious limitation of this approach is that it is really only suitable for tanks with a sand bed. It also costs a fair bit of money. Having said that, I am really happy with the final product and am now looking forward to aquascaping.

[abcha0s]

Let the fun begin. While I find it incredibly difficult and challenging, I also really enjoy aquascaping. I've been really happy with my past efforts and I am equally pleased with the success in this tank. What I do regret is that the camera really can't show the 3rd dimension and aquascaping is really all about depth. The pictures of this rock work really don't do the actual structure justice. I struggle to see the aspects that I like most, so you might need to use your imagination to see why I like my final creation.

I started with 320 pounds of BRS Dry Eco Rock and an assorment of 1/2" acrylic pegs.

.

I built a total of 4 structures before deciding that I really liked the 4th. I had a rough idea of what I wanted, but the way the rocks fit together also played a large role in the final configuration.

Version 1 - This was supposed to be a cove providing lots of sheltered swimming areas and caves for the fish. I was successful in creating what I had envisioned, but in the end it really didn't look natural.

.



Version 2 - In this one I was trying to create more of a sloped structure while introducing a more natural look. The results were somewhat successful, but not great.



Version 3 - When I see this in pictures, I like the look of it. I was going for more of a 'minimalist' look. The problem was that the rocks weren't really fitting together. It would have been difficult to place corals effectively.



Version 4 - This is the aquascape that I am keeping. It has all of the features that I was hoping to create, but most importantly it really creates depth in the tank. There is ample room for coral placement and I expect water circulation through the structure to be good.

.

.

.

.

Construction - For those who may be curious.

I did not drill or peg the rock directly. The initial placement is held together by gravity. If the rocks were not stable, I selected a different rock. After completing the structure and sleeping on it for a couple of days, I used 'Aquascape Millput Epoxy' to bind the structure together.

The peg system really worked well. I had to move them around a number of times and found myself using our central vac to clean out the dust from the holes. I also discovered that a 3 peg platform was often more stable than a 4 peg platform. It's hard to get the rock to sit fully on 4 pegs and one of the pegs is often to short or two long.

The base structure was put in place first and then everything else was piled on top of the base. The base creates the general shape and then the rocks decide for themselves what the overall structure will look like.

One lesson learned is that if I were to order the dry rock again, I would ask for more mid sized pieces. I found it difficult to use the largest of the pieces and didn't really need as many small pieces as I had thought that I might. Overall, I am very happy with this rock.

I used a total of approximately 200 pounds leaving me with about another 100 pounds of unused rock. I'll offer some of this for sale in the next month or two. This puts me at about .5 pounds per gallon which is way below the traditional recommendation of 1-1.5 pounds per gallon. Let's hope those bio-pellets work as well as advertised.

The following pictures are just for fun and show some of the stages of assembly:

.

.

[abcha0s]

I had a DSB in my 90G display and I really liked it. However, for this tank I decided that a shallow sand bed would be easier to manage.

In selecting a sand, I looked at color and grain size. Specifically, I wanted a larger grain that would not get blown around by the high flow in the tank. I selected Caribsea Arag-Alaive Special Grade Reef Sand.

.

Note: On occasion, I've had my Tunze 6205 powerheads slip in their mounting clamp and end up pointing straight down into the sand bed. When this happens, the larger grain size has basically saved me from disaster. The powerhead pushes the sand aside and exposes the bottom of the tank, but the sand hasn't been blown up into the water column. This is a good sand for high flow tanks.

I should explain that in hind sight, I think the Arag-Alive product line is a little bit confusing and I would not purchase it again. The reason for this is how the weight is calculated. What I learned after the fact is that the water the sand is packed in is calculated as part of the net weight. This could easily be as much as 25% - On a very small tank I could maybe see the benifits, but on most tanks this is just wasting money. I do like the sand, just not the fact that I paid for 50+ pounds of water! One benefit of the Arag-Alive is that it comes pre-washed - I guess that adds some value.

At this time I have added 240 pounds of sand. With the water weight, lets call this at 200 pounds.

.

.

[abcha0s]

Fish List
-----------------------------------------------

Firefish (2)............................Feb 06, 2011
Solar Wrasse............................Feb 18, 2011
Royal Dottyback.........................Feb 18, 2011
Bartlett's Anthias (1M, 11F)............Apr 09, 2011
Diamond Watchman Gobies (2).............Apr 11, 2011
Purple Tang (Medium)....................Apr 28, 2011
Amphiprion Ocellaris (Mated Pair).......Apr 29, 2011


Coming soon
2 indigo dottybacks
Hawaiian Flame Wrasses (Mated Piar)
Tangs - Yellow, Hippo, Powder Blue, Sailfin

[abcha0s]

Green Digitata

[abcha0s]

post 36

[abcha0s]

Initially I wasn't sure that I was going to have a refugium in this system. I really wanted a clean sump and had hoped to use the chamber for frags. However, with the dry eco rock, my tank started out with no life at all. I also want to keep a number of fish (anthias and dragonets) that may only be sustainable with a refugium.

[abcha0s]

Reserved

[abcha0s]

I built this for my current 90G. After testing all aspects of the system, I decided against using it on my 300G. Many of the aspects of this system were designed to allow the use of cheap paristaltic pumps (read Aquamedic). For the CWC system on the 300G, I decided that it was more effective to simply invest in a high quality paristaltic pump and the whole loop thing wasn't needed anymore. I may pull this post down at some point, but for now you can take a look if you are interested.

Continuous Water Change System

“Continuous water changes, despite their name, are not necessarily performed every minute of every day. The distinguishing feature of these changes is that water is added at the same time that it is removed. The actual rate of addition can be high or low. Reef aquarists (myself included) most often perform these types of water changes with two matched pumps, one that removes the old water and one that adds the new water.” - Randy Holmes Fraley

The plan is to build a continuous water change system that changes approximately 30% of the total system volume every month. Estimating the total water volume at 400 gallons, then 30% of this is 120 gallons. Based on a 30 day cycle, this is 4 gallons every day.

There are a number of design challenges that need to be overcome for the system to be successful.

• Proximity to tank – The holding tanks are fairly large and in my situation must be located in the water room.
• Drain – Access to the drain is in the water room.
• Incorporate chiller into system.
• Able to operate unattended for a minimum of 30 days.

In order for the system to run for 30 days without any intervention, the reservoir has to be at least 160 gallons.

The basic premise is to build a closed loop between the tank and the water room. Along the loop, there will be several key components.



• A tap for a peristaltic pump to add water from a reservoir of premixed saltwater.
• A tap for a peristaltic pump to remove water into a drain.
• A Chiller.

It is assumed that the peristaltic pumps will add and subtract water from the system at exactly the same rate (matched pumps). However, this assumption needs to be tested and verified. If the system is not calibrated perfectly, the risk is that the salinity will either rise or fall over time. (The water level in the tank is unlikely to be affected as the ATO system will ensure that the water level is constant.) If the pumps are not perfectly synchronized, there are several easy solutions including running one pump longer than the other, or adjusting the salinity of the new saltwater to compensate for the calibration error. In any event, the rate of change is so small (4 gallons per day into a 400 gallon system = 1% change) that any drift in the system should be easily detectable before the parameters wander too far.

In addition to the basic loop, there will also be a system in place for larger “batch” water changes. This system will be based on a series of valves that really just enable two additional features of the loop.

1. Enable water to exit the loop directly by way of the drain.



2. Enable new saltwater to be pumped into the loop from the reservoir.



Plumbing

The plumbing schematic helps to illustrate the overall flexibility built into the system.



All of the components are connected to unions so that they are both serviceable and replaceable.

Normal Operation:
* Open Valves – A,B,D,E,F,G,H
* Closed Valves – C,I

Batch Fill:
* Open Valves – D,E,F,G,I
* Closed Valves – B,C,H
* Doesn’t Matter – A
* Change from Normal - Close B,H - Open I

Batch Drain:
* Open Valves – A,B,C
* Closed Valves – D,I
* Doesn’t Matter – E,F,G,H
* Change from Normal - Close D, Open C

The Chiller

One of the secondary design goals of this system was to get the chiller as far away from the tank as possible. This is because the chiller is loud when running and produces a lot of hot air. Having the chiller in the water room should solve these problems. The only drawback that I see of including the chiller in the loop is the additional head pressure that it adds. The manufacturer estimates the head pressure through the chiller at 4’.

The Reservoir - Heater and UV Sterilizer

The reservoir mixing loop has both a heater and UV Sterilizer.

The heater will not normally be activated. With the extremely slow introduction of the new saltwater, I am not concerned about matching the tank temperature. While I expect it to be inconsequential, I would prefer the water to be cold to help with cooling. If I plan to do a batch water change, I will activate the heater and allow the temperature to adjust before doing the WC.

The UV Sterilizer will be on whenever the mixing pump is on (and valve H is open).

The Peristaltic Dosing Pumps

I bought the Aqua Medic Reef Doser Quad - Dosing Pump for another project that I didn't end up building. As a result, I have 4 peristaltic dosing pumps sitting on a shelf.

Initially, I really didn’t like the Reef Doser Quad. The controller has some major limitations that make the pumps unusable in most situations. For example, in the event of a power failure, all programming is lost. Furthermore, there is no concept of actual time – everything is programmed based on elapsed time. Needless to say, I was disappointed with the purchase.

In hopes of finding an easy way to control these dosing pumps with my controller, I took them apart and found them to be easily moddable. Firstly, the motor runs on standard AC power. Secondly, all of the dosing pumps are easily detachable from one another. After tracing the wires, it was pretty easy to hook up the motors to a standard PC power cord which can then be connected to a timer or controller. The original controller basically went in the garbage.

These pumps are rated for (1.5L/Hour or 0.4GPH). To achieve a daily exchange of 4 gallons, the pumps have to run for 10 hours.

To minimize any stress to the system, I will stagger this throughout the day. The cycle will be 1 hour on followed by 1 hour off for 10 full cycles. The final cycle will be 4 hours off to complete the day. (24 hours = 4 gallons)

Challenges

As with any system, there are some unknown factors. Some of the questions that I have are:

• The loop is pressurized. I’m unsure what effect this will have on flow rate through the peristaltic pump?

Limitations

• Heat - The pump will introduce heat into the system.
• Energy – The pump will consume energy
• Maintenance – Cleaning the loop will be difficult due to the length. I will replace the spaflex tubing once every year or so.

[abcha0s]

Thanks for stopping by. It's been a lot of fun for me to build the system and somewhat enjoyable to document it. Still loving this hobby...

February 2011


March 2011


July 2011


Next

*** Discussion from this point forward ***