Backyard Aquaponics
A place to discuss aquaponics

Can I use the same type of gravel for both the Grow Bed and Fish Tank?

Sorry for the... possibly obvious question.

We don't use gravel in our fish tanks at all Confuzedd... potentially it could trap uneaten feed and fish wastes... leading to anaerobic decomposition... possible release of hydrogen sulphide gas, ammonia spikes... and fish deaths...

I have gravel in my indoor tank, but for looks only. I need to clean the gravel on a regular basis, cos it fills up with crap.
If you can avoid it, do not put gravel in your FT.

Ahh, thanks again.

Weird, one of the guides I read told me to do this.

There's been a lot of "guides" and "manuals" published lately... often by people that have no idea about aquaponics, but are just jumping the band-wagon or riding the cash-cow...

I cant see that a little bit of gravel is going to cause any harm, but you dont want to lay it on too thick. Wastes will still decompose, but if you were at all worried then you could occaisionally give it a bit of a stir. Wasn't the RSG + Janet talking about it a long time ago? I thought he talked about anorobic pockets in a natural ecosystem, and provided you were reasonable about it it would do more good than harm???

Nope KEII... Janet's RSG filter was in her growbed... from memory...

There is some evidence that yabbies grow quicker with a gravel substrate so I've got some gravel in the bottom of my yabbie tank. Not enough to catch silt but just enough to cover the bottom and give the critters something to play with.

They do like to dig and fortify

So a lot don't like the idea... but what about the goldfish, do they notice the difference, like, make the tank look more natural as opposed to them being caged up.

Go ahead if you want to Confuzedd... it's just that it's going to require more maintenance... and the need to keep a careful watch on your water parameters...

Normal aquarium gravel is usually kinda small to use for a grow bed. If you really want gravel in the bottom of your fish tank (like because it is an aquarium for display as well as for Aquaponics) you could probably use the same gravel as you use in your grow bed as long as you keep in mind you will probably need to clean the gravel in the aquarium the same as you would in a traditional fish tank.

If this isn't for display, then don't worry about gravel in the fish tank, the goldfish don't really care.

I wasn't thinking about the position of the filter, just the principle of not being too worried if there are small anorobic pockets.

In principle... I think you should be worried about any anaerobic pockets... unless known, and/or contained and managable like Janet's RSG filter...

The problem with possible unknown, unmanaged pockets... are just that... before you know about it, your whole water quality parsmeters may go south ... rapidly...

IMO... I can't see any benefit from anaerobic zones, or processes with the fish tank at all...

There might be some arguement for "controlled" zones as a method of offgassing nitrates... but only within systems external to the fish tank... be it an RSG filter, bakki shower or some other external bio-filter/offgas device...

If you have gravel in the bottom of your fish tank, it WILL get full of crap, and at some stage (netting a fish) you will stir that crap up, and fish will die very quickly.

When you stir the bottom of a tank up all the gasses are released into the water very quickly = instant death. I killed a couple of trout this year when their water flow was not the best. I installed a better pump which stirred up the crap on the bottom, 3 dead trout instantly.

About the only exception is a yabbie tank, mainly because they spend all day digging through the rocks anyway, so nothing gets built up.