Hi guys,
Been a while since I've posted here. I've had my tank closed down for over 2 months, what with starting a new job and moving from London to Birmingham.
I finally got around to setting it back up this weekend, and I've decided on a Malawi Cichlid tank. The water in Birmingham seems best suited for them, and my son fell in love with the yellow labs at my LFS.
Spent yesterday cleaning the tank, then gave the back a few coats of black paint - I had some Hammerite left over from painting the patio set last weekend. Not a great idea, by the way - metal paint and glass don't mix, but it worked in the end with a sponge roller.
I've washed a bag of kids' play sand for the substrate, left it rough on the bottom - I like the look better than a flat, smooth substrate.
Now I'm looking for some rocks to create a feature in the tank - something I can build caves and hidey holes with for the fish. I've got a Trigon 190 corner tank, and I want to start the rocks off lower at the front, building them up higher towards the back.
I've seen people using ocean rock, which gives the tank a marine look - not really what I'm after. I was thinking of buying a couple of those blue/black natural limestone slabs from B&Q and breaking them up. Would this work?
Thanks for any advice.
choosing stones for a malawi aquarium
Re: choosing stones for a malawi aquarium
Limestone and sandstone are the go-to rocks for rift lake and marine tanks, mainly because they're calcium-based which helps keep the pH levels nice and alkaline.
These rocks are pretty soft and easy to work with, so if you've got a wood rasp lying around, you can use it to shape the limestone. Drilling holes is also a breeze with a masonry drill bit. One trick I've found is using vinegar to create holes - it dissolves the stone over time, leaving a nice hole behind. Just be prepared to keep adding acid as the limestone neutralises it.
I've used this method to create tubes for my fish to hide in, it's really effective. One thing to note, though, is that limestone and sandstone are typically cream or white in colour. If the rocks are black, brown, or blue, they're probably not limestone or sandstone.
River rocks are another option, but they won't help with maintaining that alkaline pH.
By the way, I feel your pain with the paint - a can of spray paint works wonders on glass, just make sure it's completely dry before setting up the tank.
These rocks are pretty soft and easy to work with, so if you've got a wood rasp lying around, you can use it to shape the limestone. Drilling holes is also a breeze with a masonry drill bit. One trick I've found is using vinegar to create holes - it dissolves the stone over time, leaving a nice hole behind. Just be prepared to keep adding acid as the limestone neutralises it.
I've used this method to create tubes for my fish to hide in, it's really effective. One thing to note, though, is that limestone and sandstone are typically cream or white in colour. If the rocks are black, brown, or blue, they're probably not limestone or sandstone.
River rocks are another option, but they won't help with maintaining that alkaline pH.
By the way, I feel your pain with the paint - a can of spray paint works wonders on glass, just make sure it's completely dry before setting up the tank.
Re: choosing stones for a malawi aquarium
The hammerite did the job in the end, just a right old pain to apply.
Thanks for the info on limestone, I appreciate the heads up. I knew limestone came in different colours, I've seen some lovely black, brown, and green pieces, but I'm not sure how the different colours affect the mineflake content.
I'd already bought the black limestone slabs before I saw your reply, so I've gone ahead and broken them up. Fingers crossed they'll be okay. I'm in the process of putting some of the pieces together now, and I'll leave them in the tank for a few weeks while it cycles. I'll be testing the water regularly to see how it affects the pH and hardness.
I've got a pretty sturdy structure going so far, but I'm always a bit nervous about the fish banging into the stones in a glass tank. I've got some black aquarium-safe silicone that I'm thinking of using to bond the stones together - do you think that would work, or should I hold off and get some stone cement?
Thanks for the info on limestone, I appreciate the heads up. I knew limestone came in different colours, I've seen some lovely black, brown, and green pieces, but I'm not sure how the different colours affect the mineflake content.
I'd already bought the black limestone slabs before I saw your reply, so I've gone ahead and broken them up. Fingers crossed they'll be okay. I'm in the process of putting some of the pieces together now, and I'll leave them in the tank for a few weeks while it cycles. I'll be testing the water regularly to see how it affects the pH and hardness.
I've got a pretty sturdy structure going so far, but I'm always a bit nervous about the fish banging into the stones in a glass tank. I've got some black aquarium-safe silicone that I'm thinking of using to bond the stones together - do you think that would work, or should I hold off and get some stone cement?
Re: choosing stones for a malawi aquarium
Thanks for the advice, I knew limestone was a good choice for a Malawi tank but wasn't aware it came in different colours, I had assumed it was all cream or white.
I've already got the black limestone slabs and broken them up, so fingers crossed they'll be alright. I've started building the feature and will leave it in the tank for a few weeks to cycle, I'll be testing the water every couple of days to see how it affects the pH and hardness.
The structure is looking pretty sturdy at the moment, but I'm always worried about the fish banging into the stones and the glass tank. I've got some black aquarium safe silicone, do you think that would be good for bonding the stones together or should I get some stone cement?
I've already got the black limestone slabs and broken them up, so fingers crossed they'll be alright. I've started building the feature and will leave it in the tank for a few weeks to cycle, I'll be testing the water every couple of days to see how it affects the pH and hardness.
The structure is looking pretty sturdy at the moment, but I'm always worried about the fish banging into the stones and the glass tank. I've got some black aquarium safe silicone, do you think that would be good for bonding the stones together or should I get some stone cement?
Re: choosing stones for a malawi aquarium
I'm not sure if that grey rock is the limestone you mentioned or not, but to me it looks more like slate. Both slate and limestone are safe for aquarium use, but if that's man-made limestone that's been dyed, then there could be a problem.
I've heard that some manufacturers make limestone bricks and blocks by compressing and gluing crushed limestone together, and while they usually don't stain or dye them here, it's possible that they might do that in other countries.
If you're unsure what it is, you could try drilling a hole in the rock to see what happens - slate is notoriously difficult to drill into, but limestone is much softer.
You could also drill holes in the rock and use PVC pipes as dowels to hold the structure together, which would allow you to assemble and disassemble the rocks as needed.
I've heard that some manufacturers make limestone bricks and blocks by compressing and gluing crushed limestone together, and while they usually don't stain or dye them here, it's possible that they might do that in other countries.
If you're unsure what it is, you could try drilling a hole in the rock to see what happens - slate is notoriously difficult to drill into, but limestone is much softer.
You could also drill holes in the rock and use PVC pipes as dowels to hold the structure together, which would allow you to assemble and disassemble the rocks as needed.
Re: choosing stones for a malawi aquarium
That does indeed resemble slate, which is perfectly safe for your tank and won't affect the water quality. However, if it's actually limestone, then it's likely that some other substance has been added to create the colour, whether that's through a manufacturing process or some other means. This could potentially leach into the water and cause problems for your fish.
Re: choosing stones for a malawi aquarium
I've been thinking a lot about the rocks I've bought for my tank, and I'm still a bit unsure. I know coltin mentioned that limestone can come in different colours, but I'm not sure if the black limestone I've got is safe. I've already started building my feature, and it's looking pretty good, but I don't want to risk harming my fish.
I've been using some black aquarium safe silicone to bond the stones together, but I'm not sure if this is the best way to do it. Should I be using stone cement instead? I've heard that this is a better option, but I'm not sure if it's necessary.
I've also been thinking about adding some PVC pipe to hold the rocks together, like coltin suggested. This seems like a good idea, but I'm not sure if it's worth the extra effort. I just want to make sure that my tank is safe and healthy for my fish.
I've attached a photo of my progress so far, and I'd love to hear any feedback or advice you guys have. Let me know if you think I'm on the right track, or if I need to make some changes.
I've been using some black aquarium safe silicone to bond the stones together, but I'm not sure if this is the best way to do it. Should I be using stone cement instead? I've heard that this is a better option, but I'm not sure if it's necessary.
I've also been thinking about adding some PVC pipe to hold the rocks together, like coltin suggested. This seems like a good idea, but I'm not sure if it's worth the extra effort. I just want to make sure that my tank is safe and healthy for my fish.
I've attached a photo of my progress so far, and I'd love to hear any feedback or advice you guys have. Let me know if you think I'm on the right track, or if I need to make some changes.
Re: choosing stones for a malawi aquarium
It's natural flake limestone so hopefully no additives are present. I've taken a few photos to help me remember how the pieces fit together. Now I'm going to smooth the edges down with a file. After that, I'll soak everything in boiling water for a bit to make sure it's clean.
I'll let it dry overnight, then I'll stick it all together in the morning. I'll have to do it in a few pieces to make it easier to move and place in the tank. Fingers crossed it all goes to plan.
I'll let it dry overnight, then I'll stick it all together in the morning. I'll have to do it in a few pieces to make it easier to move and place in the tank. Fingers crossed it all goes to plan.
Re: choosing stones for a malawi aquarium
I've finally got the design sorted, it's 55cm long on both sides and peaks at 45cm in the middle.
Re: choosing stones for a malawi aquarium
You've got a great design there, I love the look of it. I'm just a bit concerned that the rocks might shift with the cichlids swimming around, especially if they're as feisty as my labs can be - they're a handful sometimes. I've had them knock over caves before, so I'd recommend using some aquarium-safe sealant to hold the rocks in place, just to be on the safe side.