[Paul_DLS]

I've been reading about the DiY backgrounds and gathering materials for a few months now and I'm ready to submit some of my plans and questions to the rest of you for comments and suggestions. Once I start I'll also use this for progress updates & images.

I'll be working with insulating foam sheets and Quickcrete Quickwall for the background and pvc for the jets. I have a spare 55g tank to use for the layout, prep, construction, and curing. I'm using a modified Peng. 330 HOB for filtration plus whatever mech. filtration having foam around the UGJ pump intake provides. Here are some of my interests and concerns that I haven't found enough information on:

Caves:
I plan to incorporate multiple caves into the background and I did read about Satin Macy's BG in the Library, but not a lot of attention was paid to the caves in words or images. Are there reasons outside of waste build up and the difficulty of catching fish not to incorporate caves? I've seen many of the BG projects, but caves as part of the BG seem rare which is odd considering the amount of mass available within the foam. I know there is an issue getting cement to stick in caves so I'm considering inserting various sizes of abs pipe sections into the foam. This should negate the need to coat the walls and I'll angle all the caves a bit to allow waste to fall out as fish enter and leave. I can use concrete to customize the openings and blend edges with the foam so I don't end up with a BG full of perfectly circular and obvious holes.

Sidewalls:
I've seen how building the background around to include the sidewalls can really add to the 3D effect, but that creates an issue with viewing the tank sides since I don't want a nice tank from the front with foam visible from the sides. Do you just paint the sides black and too bad if subtracts from the tank's overall look? I could build the sides from the back towards the front of the tank and angle the walls away from the sides as I get closer to the front of the tank so that I could get cement coated on the foam closest to the tank sides (I wouldn't keep the outside edges of the BG flat in this case), but then I end up with dead spots for waste unless I don't allow the sidewalls to reach sand level.

Tank Bottom & UGJs:
I'll be getting a Mag pump rated at around 700gph to push 3-4 jets. I'll leave cutouts behind the BG for the pump and heater, but I've got to plan an intake solution whether it's just allowing water to flow over the top of the BG and behind to the heater & pump or some kind of screened cutouts under "rock" outcroppings.

I don't want to plan the floor plumbing layout until the structure of the background is set. I'm considering using foam on the tank bottom (must keep that in mind for BG height!) to support some rocks and if I cut the bottom foam with a margin around the sides I can get a nice deep sand look without as much gas buildup. If I do this I'm worried about my Malawi's moving enough sand around to show the blue foam, any experience with this?

Adding foam to the bottom offers the opportunity of sinking my jet plumbing into the foam, but I've not nailed the logistics of this down yet and I do not want pvc to bear the weight of a rock and become a stress point on the glass. I do want to use cement to disguise the jet heads as rock.

BG Appearance:
So, foam details are smoothed over by the cement and color is covered by algae. I'll use some buff pigment for shading even if it only gives me a neat first picture. If I ever have to sell the tank it may help. For details I'm drawing on the multitude of artistic souls who have written their name or left a handprint on a sidewalk. On the third and/or fourth coating of cement I'm thinking of trying to press a real rock with coarse details into the cement to get a reverse impression, but I have no idea if I could do this immediately after the coat is applied or if it needs to set up some first. I will be keeping the cement moist for curing throughout.

It's a bit of a long post, but I hope something in it is original and sparks some responses. Thanks for any help you can provide.

 

[IrkedCitizen]

The only thing I see about your plans is if you put too much foam that it will float.

On the bottom you can put down eggcrate/light diffuser and then you put your UGJ system on top of the eggcrate. That will disperse the weight of the rocks so you don't have all the weight on one spot. You can watch a video about it here. http://www.cichlid-forum.com/videos/eggcrate.php

You can also incorporate the intake to your pump in the background so it takes water from in front of the BG. Just need to put a screen or some kind of mesh in front to keep sand and other debris out of the impeller.

You also have to take into effect the HOB filter and how you are going to get water to it.

I am sure other people will chime in.

 

[Exevious]

The batteries in my camera are dead, I will take more detailed pics tomorrow.

My background does have two nice caves, in addition to the spaces between the large base rock carvings, which will have real rocks placed at each gap... thus creating a nice cave like effect in 4 additional spots... for a total of six caves. Mbuna real like the nice tight spots between stacked rock, which I will have 3-4 small to medium rock piles to help blend the background into the total picture. Im sure they will find several nice spots in these formations.

I will take close up pics of the cave sections when I get new batteries tomorrow.

Looking into the tank from the sides always distorts the view anyway, I made the large carvings on the edges of my background the largest, and had them come have the distance toward the front.
I will black out the the sides of the tank with the profile of the background.... Leaving plenty of room for a side view of the tank... I suppose the sides could have been coated, but I choose to utilize the sides as additional surface area for sealant. I wanted to ensure that this would stay in place.

For good light balance, and shadow effect.. I tapperred the design slightly, so that the top of the BG protrudes further than the base.

To provide for good water cirulation and temp balance I created two sizable chambers to house heaters and equipment... and also drilled several holes at steep angles, which make them hardly noticable when the BG is viewed from the typical elevated position. Also after the seperation into three pieces for installation in the tank, nice gaps were created to assist in water circulation. The filtration will pick up from behind, and dump out in front.

I have plenty of pics of mine, you can find the link in the DIY sticky thread.
I will post some pics of these notes tomorrow.

 

[Exevious]

Keep in mind when mounting smaller pieces coated foam or styro pieces, You need to have a flat glued sealing surface that is at least 85% of the largest circumference... IE: cut glue and mount it pretty close its fatest part.

Concrete is porus... water filters right through it, and the sytro or foam is very boyant... If not glued with enough surface area, parts will come loose and shoot to the top of the tank... They dont just come loose and float around... they rocket right for the top!!

 

[Paul_DLS]

I wouldn't think that an inch thick sheet of foam board with a coat of silicone would float. The eggcrate wouldn't have a float issue and would help keep the fish from making bare spots on the tak bottom, but it would make stirring the sand to remove gas pockets difficult. Maybe an inch of foam board on the bottom with cutouts for the pvc to rest and some thin eggcrate across the top of all of it.

I have a good mix of chunky and flat rocks to add. Using the tank sides for additional adhesive surface is a sound idea. Painting the sides only where the foam would be visible is a possible compromise. What about ignoring the existence of the glass walls and continuing the background outside of the tank for the tank sides only? Everywhere the foam adheres to the interior tank sides match that profile with an inch or so of foam on the outside rounded and cement coated to match. I'd have to wait for the interior BG color to stablize (algae/wet) then paint the exterior work to match. In general I'll taper the background from top to bottom for shadows with a few protruding exceptions to provide two semi-divided open swim areas.

I'll start with enough foam board siliconed together for 10" of rock depth I'll hack into and try to avoid having to glue on extra pieces. I've planned for keeping pump, heater, and HoB intake behind the BG with disguised and screened intakes. I have to plan around the HoB carefully to avoid a circular flow of filtered water:

 

[IrkedCitizen]

Well as long as you put something over the foam like the eggcrate so your fish cannot pick at the foam. Because they will.

Also, the sand in the eggcrate won't have that much built up gas. A lot of people use eggcrate. If the gas build up was that huge they wouldn't use it. Why risk killing your fish? Ya know.

 

[Paul_DLS]

Well as long as you put something over the foam like the eggcrate so your fish cannot pick at the foam...
...A lot of people use eggcrate. If the gas build up was that huge they wouldn't use it. Why risk killing your fish? Ya know.

Thanks! As funny as it may look I'd rather not find a floating blanket of foam bits in the tank and since my search for Egg Crate Death Syndrome came up empty I imagine you're right about that as well.

 

[Exevious]

Ya.. the egg crate is barley even 1/4 inch tall.. and cichlids will keep the sand stirred up pretty well, cause you to have to push it back into place every few days.

I have yet to find any gas buildup in my tank.... But I do have a thin layer of sand, not as deep as many other I have seen.

 

[IrkedCitizen]

Thanks! As funny as it may look I'd rather not find a floating blanket of foam bits in the tank...

yeah that or it could clog the intake to your filters.

 

[Paul_DLS]

I picked up materials a few days back and got started. I changed my layout for equipment opting to wall off the left corner for heating and filtration. I'll likely look into an in-tank sump setup later. I incorporated some PVC fittings and hacked into the foam for caves.

Foam backing, outcroppings, and caves arranged before bonding.

All bonded using DOW's "Great Stuff".

Results after some trimming and the propane torch.

Because depth is difficult to show in a 2D image here is a shot from the bottom.

And the test fit after torching.

Here are some things I've learned:

DOW's "Great Stuff" bonds with polystyrene better than silicone.
I initially ran out of "Great Stuff" before bonding the white apartment complex on the left to the pink polystyrene backing and went with silicone. I applied a 1/8 thick coating spreading it and pressing into the foam with a putty knife before putting the pieces together and weighting it down with a 50lb bag of sand. 24 hours later I picked at a small amount of silicone that had oozed out around the edges and it lifted away from the foam without a lot of effort. I tried pulling them apart and succeeded with a great deal less effort than I was hoping for. I peeled off the silicone layer and got another can of "Great Stuff".

As great as "Great Stuff" is there are some drawbacks; the expanding foam dries around the edges first due to air exposure and the center continues to expand which created a couple of bulges in the foam board used as a backing. Using less, adding weight, and/or drilling a few holes through the back before application may prevent this.

Unlike what I've read elsewhere "Great Stuff" does NOT react the same as the polystyrene foam when heat is applied. It is very heat resistant and will remain long after the polystyrene around it has melted away. If using "Great Stuff" it may be best to depend on a knife and rasp to physically shape the background rather than torch it. I believe it's considered a fire retardant although it does catch fire when a direct flame is applied.

FYI: "Great Stuff" for around doors and windows does not expand as much, but also doesn't bond with plastic-like materials as well if at all.

I'm stuck using silicone to attach the panels to the back of the tank, but I'm going to drill into the foam to make anchor points I can fill with silicone.

Now that I have a profile to work around I'll start laying out the UGJs.

 

[Paul_DLS]

Center and right BG panels after a coat of Quickwall.

Left panel with its first coat and the center and right panel's second. I used color to help be sure I put a complete second coat on and for initial enjoyment before algae.

UGJs laid out. I over heated some of the fittings while getting them into the nozzle shape and had to reheat the opposite end to get them to fit over the pvc pipe. Only one was so loose I felt compelled to use pvc cement.

 

[Paul_DLS]

In my efforts to go beyond reasonable I decided to make rocks around the jets.

Test fitting support system.

I needed a way to keep the jets from getting clogged with cement and came up with foam bits to recess the jets into the "rock" then cover with plastic which is held in place with rubber bands. To make things a little easier I pushed toothpicks through the foam and into the jet openings to hold the foam in place while wrapping with plastic.

Close-up.

I used heavy-duty foil as a form with the jets upside down and filled with Quickwall. I tried to keep the background in mind and moved the foil to give room where needed and made sure to push part of the foil right up against the plastic covered opening.

After 10 hours I removed the foil and while the cement was still workable made adjustments like clearing the openings, removing excess cement from the pvc that would come in contact with the tank bottom, and scraping cement from areas that would interfere with the BG (hopefully). I set the jets into the spare tank with the pump resting on the opening and used the UGJs to circulate salt water around for a few days before taking a torch to them to soften/remove the fiberglass strands sticking out of the cement.

from the other side

with a jet opening featured

 

[Paul_DLS]

BTW- The jets now weigh 5--7 lbs which I don't see as a problem, but the cement would have been more workable after drying if I had used hydrogen peroxide instead of water to mix with the cement. I'm anticipating a bit of a fit issue with the background and one of the jets...we'll see.

 

[kewlkatdady]

WOW...

Looks very cool.

Can't wait to see the final product, and I love the idea of crete around the jets...

 

[Paul_DLS]

I got side tracked on refurbishing the livingroom drywall and trim.

I just didn't have confidence in the silicone to foamboard bond, although my test case may have gone poorly due to evenly spreading the silicone rather than zig-zaging a bead that allowed spaces for outgasing. I did have confidence in the silicone/glass and silicone/silicone bond so I opted to burn anchor holes into the back of the foamboard pointing diagonally down and toward the front of the tank.

I cleaned the glass with alcohol, filled the holes with silicone and immediately put on a a thick bead of silicone connecting the dots(anchor holes).

I installed the UGJs and the three BG sections with the tank on its back and added a few rocks for weight. Installing the tightly fitted sections was made a lot easier by breaking a bit of the top corner off the last section of BG. I allowed this to cured for a week sometimes running a box fan on the the tank. The curing silicone smelled for 4 or 5 days. After that I was ready for a fill test which has been going for the last few days.

Oops, left the living room curtains cracked!

 

[MightyWarMonger]

wow that came out real nice and I like what you did to hide the UGJ system great job can't wait to see some fish in there :thumb:

 

[spotmonster]

That's the best idea I've seen for hiding those ugly jets. I always thought they looked silly sticking out of the sand and you solved that problem! Great job.

 

[Floridascuba]

nice looking tank.

 

[Paul_DLS]

Six days and four water changes later and the Ph is still off the scale.

 

[jay415]

Looking good! :thumb: