# Texas holey rock?



## Cama (Aug 2, 2012)

Hi, I have a general question that I can't seem to find an answer too. I am setting up a 75 gallon cichlid tank. I am going to be using Texas holey rock as the hardscape. I was wondering how many pounds can the bottom of the tank hold? I plan on using about 120 pounds... Is that too much? Thanks... Also what would be the best way to place it in the tank? Should I put something under the rocks so that they don't rest right on the glass?


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## jeffm02 (Feb 6, 2013)

The tank will hold that much rock no problem. With cichlids make sure you put all your bottom rocks directly on the glass. Cichlids dig and will topple rocks if they dig underneath.


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## mantiz (Oct 14, 2012)

I cant really tell you how much rock you can put into your tank but that sounds like a LOT of holey rock to me. I haven't used it but I didn't think it was very heavy.

However, there are a few things that you can do to reduce the risk of a crack in the bottom of your tank. This is from both personal and research so some people may disagree or have other ideas.

1. Before you put your tank on the stand surface you can put down a layer of foam insulation (your choice on the thickness), but the idea is to reduce any irregularities between the stand and the bottom of the tank.

2. Put down egg crate (the plastic grate you see in florescent light fixtures or ac ducts sometimes, its cheap at HomeDepot) before you add your substrate. This will help distribute the weight of your rocks to make sure you don't have any pressure points on the glass.

That's about all I know from experience.


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## pyrrolin (Jan 11, 2012)

Sounds like good solid advice to me. I would not put the rock right on the glass, I like the eggcrate idea, but I would also have gravel or sand on top of that to further buffer any pressure points.


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## Ryan.Wilton (Dec 12, 2012)

+1 to pyr. Use some eggcrate to make an even foundation, cover it with sand and there should be no issues with stabilization. The cichlids will dig at the rockwork and the tank will hold 120lbs no issue.

One thing to remember though is that the more weight in the tank, the less water the tank actually holds. 1 gallon is 8lbs. By this logical, 120lbs of rock loses 15 gallons of water, making your tank only a 60gallon aquarium. When you add the sand into that mix (I assume sand and probably at least 50lbs of it) you lose another 6 gallons.

Personally I don't think you need 120lbs of the stuff. That seems like over kill, I mean after all it's not a SW reef, so all that rock isn't really required.


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## Cama (Aug 2, 2012)

Thank you all for the advice, I have ordered 120 pounds but may not even use all of it in one tank, it will all depend on how big the pieces are and how I position them. Any extra may go in a different set up, I was just curious to k ow about weight in the tank. I will consider all the advice, most likely use the egg crate seeing as it will distribute the weight over the whole bottom of the tank. In regards to the foam under the tank, what's the best kind to use? And how thick? I have made my own stand, it is level and even but I do notice a few imperfections I t he top of the plywood... Thanks again everyone!


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## Ryan.Wilton (Dec 12, 2012)

You can go get the insulation foams from Home Depot. That stuff works the best They're generally an inch or so think, but I'm sure you can trim it down to size. That's what you're meant to do in all honesty, measure, cut, measure again and make it as even as possible. I've never used the Styrofoam I've heard it beneficial if you have warped floors, are in an area that suffers from earth quakes or if the tanks in a high traffic area that may cause the water to become disturbed from people running by.


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## Cama (Aug 2, 2012)

So where would I put the foam? Do I put it on the floor under the stand, or on the stand under the tank, In between the tank and the top of the stand?


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## Ryan.Wilton (Dec 12, 2012)

Between the tank bottom and stand top. Personally I don't find it that useful, but that's because I'm cautious around my tanks. A secondary solution is Polyester foam (filter floss) that you can buy from Big Als. Layer it in the same spot but there's minimal cutting to be done, as well the weight of the tank will just flatten it out evenly.


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## snaggle (Feb 19, 2010)

If you have a standard style tank (with the raised bottom) there is no need to use foam other then as an insulator. if you have a flat bottom tank then there is a need to use it because even a small grain of sand could cause a pressure point on the tank.

There was a youtube video about 5 years ago of some guys in the states loading over 100Lbs of slate in to a 10 gallon tank to show the strength of a small tank so I am sure you have no worries with 120Lbs in you tank.


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## jeffm02 (Feb 6, 2013)

I have put rocks directly on the bottom of my tanks for years. Just place them gently. They may scratch the bottom but it gets covered. Egg crate and sand don't mix I've read. A lot of bacteria builds up in the sand and you won't be able to properly stir up the sand to release all the toxins. Plus once your cichlids start sifting and moving sand you'll be able to see the egg crate.


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## VPM3 (Aug 9, 2012)

Where are you ordering your texas holey rock from?



Cama said:


> Thank you all for the advice, I have ordered 120 pounds but may not even use all of it in one tank, it will all depend on how big the pieces are and how I position them. Any extra may go in a different set up, I was just curious to k ow about weight in the tank. I will consider all the advice, most likely use the egg crate seeing as it will distribute the weight over the whole bottom of the tank. In regards to the foam under the tank, what's the best kind to use? And how thick? I have made my own stand, it is level and even but I do notice a few imperfections I t he top of the plywood... Thanks again everyone!


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## Newobsession (Nov 17, 2010)

I would strongly suggest NOT putting sand or gravel down first to "cushion" the rocks as earlier mentioned. I just finished setting up a cihlid tank that has the entire back stacked with rock. Cichlids like to dig and if your rockwork is sitting on top of the sand, then as they dig around them you open yourself up to the possiblity of them underminng the foundation or balance of the rocks and them crashing down (as much as they can "crash" under water, but you get the point) unless you are planning on siliconing the structure together, but then you don't have the option of future rearranging, or even pulling a section apart if needed to get to sick/dead/hold fish etc. 

I can't speak to the bare vs eggcrate and bacteria issue. I prefer eggcrate, if nothing else I find it increases the friction between the rocks and the base of the tank so again less worries about things shifting.
When I did my tank I put down teh eggcrate, filled it with sand (then scraped off the sand even with the eggrate. I have pics if you want) then stacked my rocks, making sure that I placed them in a manner that they were (pardong the pun) rock solid. If you can wiggle a rock in place when stacked, then fish can possibly move it and anything on top of that can move etc etc. Just my 3 cents worth..which I've rounded up to a nickle since we've eliminated the penny .


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## Newobsession (Nov 17, 2010)

Ryan.Wilton said:


> +1 to pyr. Use some eggcrate to make an even foundation, cover it with sand and there should be no issues with stabilization. The cichlids will dig at the rockwork and the tank will hold 120lbs no issue.
> 
> One thing to remember though is that the more weight in the tank, the less water the tank actually holds. 1 gallon is 8lbs. By this logical, 120lbs of rock loses 15 gallons of water, making your tank only a 60gallon aquarium. When you add the sand into that mix (I assume sand and probably at least 50lbs of it) you lose another 6 gallons.
> 
> Personally I don't think you need 120lbs of the stuff. That seems like over kill, I mean after all it's not a SW reef, so all that rock isn't really required.


This math doesn't actually work this way. While a gallon of water does weigh in teh neighbourhood of 8 lbs based on density, it doesn't mean an 8 lb rock would take up a gallon of volume, unless it had the same density of water. In which case it wouldn't sink which obviously they do. ( What else floats? Small rocks! Churches! ~ just something that came to mind ..for other Monty Python fans out there who are giggling like I am)


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