Rocks!

[scifisarah]

Here are today's prospects from the yard. Right now I have the tank set up with limestone rocks from my yard, but I think I'm going to try switching to these mostly granite rounded ones. I also might also try white granite rocks with black specks - I have tons of those in the yard and think they'd look cool with the black sand. I'll get them ready and then put them in with the new fish I get this Saturday at the auction so hopefully my current fish won't feel it is their territory anymore. I love a good rock almost as much as the fish themselves so I am glad I have been hoarding them all these years and can put them to good use. I have hundreds more at my disposal. 

[RichE]

Field stone, I love it. If anyone ever is looking for some on the cheap stop by a local farmer, they hate these things, because they seem to pop up in every field when they plow it every year.

If not the Local Landscape supply yard you can get them cheap

IMO They make a tank look for natural

The ones you posted are just the perfect size:)

[Ron]

Those rocks rock! 

[GrizzlysDad]

Those rocks rock! 

Ditto!!!!

My 190g in my living room is set up as a Malawi reef with many types of mbuna. I have one large piece of driftwood in the center and the rest of the tank has somewhere around 400lbs of field stone...actually, I want to add more rock in the Spring.

{I know, I know....where are the pics???  }

[scifisarah]

My husband is worried that if I put too many rocks in there, it will be stressful on the tank. As long as the edges of the stone aren't in contact with the glass surface on the bottom of the tank, do I have anything to be worried about?

[GrizzlysDad]

My husband is worried that if I put too many rocks in there, it will be stressful on the tank. As long as the edges of the stone aren't in contact with the glass surface on the bottom of the tank, do I have anything to be worried about?

As long as the rocks are stacked in a way that any digging done by the cichlids will not cause shifting or falling, you will be okay.
I once had a 55g (48"x12" footprint) literally stacked top-to-bottom and side-to-side with field stone...no issues.

[Ron]

My husband is worried that if I put too many rocks in there, it will be stressful on the tank. As long as the edges of the stone aren't in contact with the glass surface on the bottom of the tank, do I have anything to be worried about?

The two main concerns would be rocks touching the glass or the structure collapsing and "touching the glass" LOL. Keep in mind that when you add 100lbs of rocks to the tank you're not increasing the weight by 100lbs, but 100lbs - the weight of the water that they take up (~8lbs/gallon IIRC). So yes the tank weight ends up heavier, but not as significantly as you may first think.

Another thing to consider though is that if you have a 60 gallon tank, but you fill it up 1/2 way with rocks, you've only got about 30 gallons of water. The process of waste --> ammonia --> nitrite --> nitrate, in the end relies on the nitrate levels being diluted by your water volume. If there's less water overall relative to your stocking rate, you may need to do water changes more often.

As far as rocks displacing water volume, this doesn't really apply to the stocking rate from an aggression standpoint, as the rockwork helps break the tank into more territories and can help reduce aggression if done correctly.