madmark285

Thanks for your reply. What I may do for future projects using this glue, cover it with silicone and whatever subtrate you are using.

I believe J-B Weld WaterWeld epoxy putty is safe for aquariums.

Big thanks for all your work. Specifically for this one, the company Gorilla Glue makes different products including a version of super glue. But what about their main product, the moisture activated polyurethane adhesive? The SDS (?) data sheet says it is toxic to fish. But many other have said that once fully cured (~ 1 week), it is inert and safe for aquariums. My opinion, moisture activated polyurethane works better than silicone when mixing with substrate for hardscape projects. Mix together with damp substrate then cover it with regular substrate as it cures. Here is an example of a cave I made. I used a balloon filled with sand as a mold, a white sand & polyurethane and cover it with gravel.

I did notice that, well done and a toast to PVC! I built a sump filter/overflow boxes with PVC material from Home Depot.

Nice tank! I see a canister filter, what are those 3 pieces of PVC pipe hanging in the tank? Is that a DIY project or something you bought?

Nope, I just misted them with water before taking a picture. This is for a 75 gallon Mbuna tank, I plan on stocking it with 4 colonies of Mbuna, 6 per colony (a total of 24 fish). the substrate will be white aragonite. so what are your plans for your tank?

Understood, that make sense. I just suggested the plywood if you are concerned with cracking the bottom of your tank from the weight of the rocks. If you got some huge rocks going in, put them in the corners of the tank to reduce the load on the glass. Gotta love free rocks which can be hard to find for many of us. I got mine from a construction site along a high voltage transmission line right-away. No worries about nasty chemicals like round up, it's just overgrown weeds. This is the latest layout in my project:

I missed that line, an old tank may not have tempered glass. If you can put a plywood sheet on top of the stand, I suggest this. Put some clear package tape on the plywood then apply a thick bead of caulk to it. Then set the aquarium on top of the plywood before the caulk dries. The caulk should help support the bottom. If you need to remove the tank, the caulk should not adhere to the tape. You could also put the tape on the bottom of the tank, same idea.

This guy from KG Tropical put ~600-800# of rock in a 240 gallon tank, tempered glass is very strong. The standard advice other have mentioned, put a egg crate ceiling light panel on the bottom to eliminate pressure points and to distribute the load. I Built The PERFECT Tank For Cichlids, Yellow Lab Aquascape Another suggestion I have, using silicone caulk, attach a piece of PVC pipe to the bottom of the tank. Now set the rock on top of the PVC pipe. If you have fish which like to dig, no chance the rock will come crashing down on them. And this makes cleaning under the rock much easier, no need to dig the rock into the substrate. I did something similar for smaller rocks, I glue the pipe to the rock: No, that's not a potato! It's a rock! End results: So the rocks stay in place in the sand substrate. EDIT: I plan on putting ~150# of rock in a 75 gallon tank.

Just an update, I finally back on this project. Here is a general layout of the rock structure I will be using. Not shown is this photo, the supporting PVC structure to hold the rocks and create the condo, thats next on my agenda. So the rocks are laid out in a semicircle, there is a open space on the front and side walls. The gap you see between the rocks will be the entrance to the condo which are under the rocks. This whole structure will be ~3-4" off the bottom of the tank. Common feedback I am getting from many... When a male Mbuna goes rouge and start terrorizing other Mbunas, I should not expect that the terrorized Mbuna will or can hide in a condo to getaway. My current design is a 3 story condo complex where us human would claim a condo for protection. This may not work with fish 🙂. So does using all the space for 26+ condo really make sense? So what I can do. In the mold I made to build this, pack sloping sand along the front and sides shown below: The sand acts as a mold for the expanding foam, the opening you see here under the rock will be foam. So this will create a ledge surrounding the rock structure for the condos. Kinda like a moat around a fort. I hope this helps in the line of sight issue, a terrorized Mbuna can swim under the ledge to get away from a rogue male. So the bottom line, this will reduce the number of condo's but create a common space where I hope any Mbuna can hide out. Any thoughts will be appreciated.

Yes we do and thanks so much for that link! Finally someone else gets it, make a Lake Malawi tank ie: all rocks! I also have the same problem as John, finding rocks and I need more rocks! I did find a bunch of black rocks, may go back where i got them for more. I did start a journal last year, here the link: Mbuna Condo Below is the look I am going for: So the bottom layer of rocks are set in a layer of foam. This is version 1 of the PVC condo structure, I am currently working on version 2. So concept here is, stuff a balloon filled with sand in all the condo then stack a layer of the base rocks. Then pour foam on the whole frame. Then of course remove the balloons. What John says is so true, trying to find the right combo of rocks stacked to make a cave is very difficult. So I am cheating.... Thanks for the tip! I plan on using Great stuff foam as a base filler then 2 parts pourable foam (3# density) I got from US Composite. All the foam will be coated with white silicone caulk covered with aragonite substrate. The US Composite foam is for marine application.

Much more complicated. Under the rocks will be caves (I am calling them condo's) built using PVC material for the Mbuna. The rocks will be held up by a bed of foam (a combo of great stuff and 3# density polyurethane foam). The goal is to get 22-24 condo's in the tank. The pourable foam will also create a slope effect. So adding buoyancy is not the main objective, just a side effect.

OK, stupid question time... I going to spray a bunch of Great stuff foam and set a large 10# rock on top of it. So when the tank is filled with water, that should reduce the load on the bottom of the tank ie: the effective weight of the rock may be 7#. Of course too much foam and the rock will now float. This is for my Mbuna tank I am building (75 gallon), the entire bottom will be large rocks. It will be a total of 100-150# of rocks. Am I missing something here? Here is my work in progress

Of course this is the best way to stock your tank. But this doesn't always work when buying fish online. Aqua Huna has reasonable shipping rates but these cost will add up if making multiple purchases. So my question is, how to prepare your tank for a initial big purchase? You can buy a big bottle of ammonia in a bottle and keep dosing your tank for an extended period. You can put food in the tank and let it rot away. My plan for a 75 gallon Mbuna tank, i have already started conditioning the K1 media (fluidized bed) in a 5 gallon bucket. Once the tank is set up, I will run it for a month or so before i buy the fish. Just before buying the fish, I will heavily dose the tank with ammonia. On a positive note, 20-24 juvenile Mbuna cichlids will have a much lower bio load than adults. So as the fish grow, so will the bacteria colonies. Good luck!

One more on cave structures. I see alot of tanks where people strategically stack up large rocks to make small caves. This is alot of rocks and finding the right combo of rocks which fit together can be frustrating. For my Mbuna tank, I will glue together a bunch of PVC condo and just use large rocks as a facade as shown below (work in progress). This rock wall will use foam between the rocks but for something more simple which just sit on the bottom of the tank may not require foam. To clean the condo, just remove the rock facade and stick a siphon hose in the condo.

If interested, I made some caves. Here is the link: Tiger Barbs on Strike! They demand a cave! My current project is 75 gallon Mbuna tank which will have ~24 caves (I call them condos). I made the condos from 4" thin wall PVC shown below. This condo is 4.5" wide, 2 3/4" tall. So I cut a small piece of pipe and put it in the oven at 210 degrees. I made a form using 2x4". So heat up the PC, slide it over the form and press down. To make one with a back on it, you could cut a 8" piece of pipe and make the form 4" long ie: 1/2 the length of the pipe. Just push the back of the pipe together while it is hot. Note: if you want a bunch of caves on the bottom of the tank, I would think about connect a piece of pipe to the back of the condo and connect it to the water return line from the sump. FYI, this is the form I made, the round edges are optional.

Not sure if a 37 gallon tank (20" W x 18" D x 24" H) is big enough for Mbuna cichlids but if you can build a rock wall with lots of caves built in it, the mbuna's will use the vertical space. The 56 gallon tank (30" W x 18" D x 34" H) would be a better option. What I see from pictures of Lake Malawi, mbunas are living in the crevices between huge boulders around the islands. So living in vertical space is somewhat natural for them.

Do you enjoy doing this kind of work? Personally I enjoy restoring hardwood floors, I find it very rewarding. Polish that tank up and it will look far better than a Aqueon glass tank, I love the curved corners on acrylic tanks.

The live rock may be dead rock by now but... can't you just re-establish the bacteria colonies in the rock? Not sure why buy any more.

I agree, Harbor freight sells a Compact Palm Polisher for $18.

A jig saw will cut the acrylic. I would cut a small section so you can use 2 18" waterproof light. The light should cover up the cut which may be ugly. The above light is 4 3/8" wide, you may not need a cover for the big openings.

I made 2 orders with Aqua Huna, 2 out of 15 Odessa died, 3 out of 12 Forktail Rainbow died (they were very young). The Panda cories, Hillstream loaches and tiger barbs were fine ie: no deaths. To quarantine freshwater fish, just setup up a temporary aquarium with a sponge filter and leave them in there for a month. Other may have better advice on how to medicate them if needed. If you just have 6 Tiger barbs, I would not use a quarantine tank. Edit: For my upcoming Mbuna tank (75 gallon) I am working on, I plan to make one big purchase of 20-24 juvenile Mbunas online. The selection locally is limited and expensive. The bio-filter will be well established using ammonia in a bottle.

Yes, they ship via priority mail and only charge $20 for shipping. I live in western New York, Aqua Huna is in Washington state. They dropped them off on Monday night at USPS, I got them on Wednesday. I bought 15 Odessa, 2 of them died. Mark

Odessa barbs! They are just as active as tigers, quite the frenzy at feeding time. I got some from Aqua Huna

The 40 Gallon breeder is nice as it has 18" depth, you can plant heavily in the back of the tank and still have plenty of open swimming space in front.