How Much Is Too Much Hardscape?

[Mitch_ScruffyCityAquatics]

I have a bunch of river rock that I want to stack up (only three high at the highest point). They are large rocks. Like 8” across on some of them. I have a Marineland 75 gallon from Petsmart… Do you think it’s too much weight to have 12 or so of these? Specifically if I stack most of them up on one side. There is gravel substrate that the rocks will be sitting in. 

[DiscusLover]

On 10/10/2022 at 10:07 AM, Mitch_ScruffyCityAquatics said:

I have a bunch of river rock that I want to stack up (only three high at the highest point). They are large rocks. Like 8” across on some of them. I have a Marineland 75 gallon from Petsmart… Do you think it’s too much weight to have 12 or so of these? Specifically if I stack most of them up on one side. There is gravel substrate that the rocks will be sitting in. 

It should be fine in my opinion.

[OceanTruth]

I’m no expert, but I wouldn’t worry about it. It’s not an apples to apples comparison, but I once saw an aquascaper use a single 50lbs rock in a rimless nano tank long ago. I thought he was a mad man, but he had the tank running for a long time and it actually looked beautiful. I never would have believed the tank could support that weight let alone have space for substrate, plants and some nano fish.

[Scapexghost]

Look at some aquascaped tanks. They're like 75% hardscape. I wouldnt worry.

[Mitch_ScruffyCityAquatics]

On 10/10/2022 at 2:07 PM, Scapexghost said:

Look at some aquascaped tanks. They're like 75% hardscape. I wouldnt worry.

That’s what I keep telling myself! 

[Flumpweesel]

Just be careful with the stack large rocks can do damage if they fall. 

I had bulldozer goldfish that would knock pebbles the size of coke cans over. I made sure they could hit the walls of the tank. Gravel would protect the base.

[Patrick_G]

You could try using a plastic light diffuser to spread out the load. I’ve seen that in lots of YouTube aquascapes. In my 75 I used some closed cell foam padding under the base rocks. I’m not sure if it’s necessary but it made me feel better. 

[BlueLineAquaticsSC]

I’ve used plastic light diffusers when I do really heavy rocks (like 30+lbs) they disperse the weight and also create a barrier between the rock and glass. With rounded river rocks it shouldn’t be a problem but more jagged rocks can have sharp points and if they settle the wrong way, to much weight behind a small point (psi) will break the glass.