Backyard Aquaponics
A place to discuss aquaponics

Came across this in my reading. I do put rocks in my current pond ... not yet AP.... and have found that it affords the babies a natural place to hide from a visiting comorant. I have been wondering if I should try it in my AP ponds even though they will be undercover .......so this caught my attention..... This might aid bacterial activity. This is about an outdoor garden pond but it gave me thought. I expect most to shoot down the idea but it interests me enough to put it out there to see if anyone has tried this. Comments?

Taken from...http://www.pondgnome.com/Myths.htm

in a lightly stocked ornamental pond, I totally agree that rocks are good.

I doubt that you really want to go there in aquacultural tanks since any objects on the bottom of the tanks will tend to stop solids from moving to the drain and going to the grow beds. Also, any bacterial action or decomposition happening directly in the tanks is going to compete with the fish for dissolved O2. My personal vote would be to keep the rocks for the grow beds and perhaps only rarely use such in the bottom of perhaps a breeding tank or something that has supplemental aeration.

I want to try it up in the shallow end in one corner. My pond will slope from 1 meter down to 2 meters so that could help solids removal and the other stuff would become water soluble... nitrates are aren't they? I was thinking it might give the young a chance of survival and also increase nitrate conversion enough to add some plants in cages along the edges of the pond..... a sort of living larder for the fish but protected enough from being totally demolished because of the cages.... I could be completely on the wrong track admittedly... it just works so well where they are now. Your warning about DO is worth remembering.

If the rocks are at the shallow end where the clean water is splashing in from the grow beds then it might be ok on a trial basis. Try to do it in such a way that you can un-do it if it proves a pain later.

Oh, just had a little thought about your system. You might want to plumb some bottom drains from your tanks down to the sump so that if you need to drain one of the tanks, it will be easier than having to lug a submersible pump in to the tank and run the hose out somewhere. This might be easier to deal with using simple valves for when you need to harvest fish (would be tricky in a 2 meter deep tank) or if you need to remove said rocks or do other repairs.

I have tried rocks in my small AP bathtub, they just let a whole heap of gunk build up. It does give you more surface area for bacteria (thats how aquariums work), but it makes a big mess when you move them later.

I would place the rocks into a crate of some sort, so they can be stopped from spreading all over the tank.

Would the plants growing in the fishpond be using the same nutrients as the ones you want in your growbeds?

Rather than using gravel and rocks for fish hides maybe something larger like pipe offcuts would achieve the same goal. In AP don't we want all the muck to end up in the growbeds?

Hmmm. I have rocks in the FT of my barrelponics system. That's the one with the gunk buildup... Time for some cleanup!

Yes. I must think about this........ Thanks TCL

That is a neat idea OBO. Easier to remove later if I change my mind. When you used rocks in your AP bathtub did you see any benefit to the system?

Hi T!

Yes the nutrients are mainly aimed at the GBs.... but I suspect I would be able to produce an excess of nutrients with my planned design and so was looking for ways to offset this with extra grow area in the actual pond which could make things a bit more varied for the fish too.

I have used pipes in my current pond as well as rocks but the rocks seem to aid the smaller fish better because of the varied sizes of hiding holes.

Hi Karen, Have you seen any benefits so far? I understand the drawbacks... clean up .... but there must have been a reason you put them there in the first place.

I had just gotten a load of gravel, and wanted to do do something with a bit of it.
It also made some of the fish easier to see, and I thought some of the catfish might like rooting around in it. Now I have a crawfish in there, and I wonder if it likes to root around in the gravel.

But no, I didn't have a decent reason.

Rocks were in mine just to be cool Everyone else with aquariums had rocks.

I have been thinking about your idea to put the rocks in a basket OBO..... guess I also want cool ... ... cos of the young....

But instead of putting them in the bottom of the tank I raise the basket close to the surface.... the young like swimming there anyway... and can dive for safety.

Or even better....
Have some plants around the edge in baskets hung from the side but a couple of the baskets hold rocks instead.....
Or even better still....
the base of all the baskets is rocks.... better be strong!!! and the water plants on top.

All the waste will still collect below.

I know this sounds a little way out but have a hunch there is something to this..... so going to try.... can always take the rocks out if not worth it later.

Surface for bacteria converting to nitrates right by the plants but giving safety to the young. Hmmmm.... I guess a kind of pond GB for water plants with very large grow media!

Just had another thought... no need for strong baskets... build a sloping ledge all the way around with a basket guard.... first rocks on the ledge ....big rising up to smaller until pea sized...and then the plants.... especially plants that li'l uns find tasty... hey! Come on! This has to be a good idea! No.... a great idea! LOL