swap out / changing substrate in a planted tank? - anyone ever use Seachem Onyx sand?

hey guys.

so, my tank is set up with silica sand as i didnt intend to have live plants when i first started.

down the timeline...something when off track and now ive got 6-7 different types of live plants and always in the back of my mind i keep thinking about changing the substrate for something that will help plant growth rather then just to stop the plants from floating around.

has anyone got any experience of swapping out gravel in a full planted and fishie tank??

would love some input as i came across a few bags of seachem onyx sand and im seriously thinking about maybe biting the bullet and getting rid of the silica sand gravel in the tank. The colour is nice and black and the grain size seems quite similar to silica sand.

therefore:

1) tell me your stories about what/when/how you swapped out gravel in a mature/stable planted, live fish tank
2) any thoughts and feedback on how good seachem onyx sand is? - am i correct that it has no nutrients? whats the point of it then?? - anyone used in the past or presently using?

thanks all!


EDIT:

and also tell me if you dont think its a good idea and reasons why! - want all input on this

thanks

 

According to the Seachem webiste, Flourite Onyx is very high in Magnesium and Calcium. The red flourite is higher in Iron than the black ones.
As far as replacing the substrate in a mature tank goes, I've only done it with a full tank rescape where all the fish and all the water was removed first and the filters kept running in the water that I kept. The danger is that your substrate could make up a big part of your biological filtration, so you run the risk of having your tank cycle again when you add the new substrate. How much filtration do you currently have in the tank?

 

I cant comment on the onyx sand but I did a complete re-scape, including substrate replacement on my nano. this included removal of the current substrate, 90% of the water and the fish. filter was kept running in tank water for the couple of hours it took to rescape.

I then added the tank water, filter and fish back to the rescaped tank and help my breath. LOL. I did up the water changes for the first week though.
if the tank did a mini cycle it was very small and the fish wasnt affected at all.

 

Use some off your existing matured subtrate to get things going on the biological side. Add a light sprinkling of worm castings, guanosol, chemcult and Osomocote if you can get it, on the bottom glass. Cap this delightful broth with Flourite and boiled/cleaned river sand..

Ps. Take absolutely no responsibility for this menu, but it seems to be working for me..lol

 

Ah yes Trevor I see you did do as the pro's told you lol (WBS)

 

i have recently matured an external canister for 5 weeks and put old filter media in the canister.
thank is 60L, i have a Tetra EX600...allegedly 600LPH
the current silica sand is ancient....i suspect you are right that a lot of my bacteria will be in the gravel.

i will have to rethink when i do this....maybe not so soon.


with regards to plants...do i remove them all as well..some of the root structures under the gravel is very VERY tangled and well established....can i be a bit rough with them? is there no fear when pulling them out?


as for the gravel - do i just scoop it out by hand? what is a good tool to use effectively and safely to get the silica sand removed as fast as possible.


where can i get guanosol? builders warehouse plant section? aquarium safe?


thanks

 

Scoop as much as you can by hand/with a bucket. You'll find when you get near the end the sand starts scratching the glass as you scoop, making that grillerig screeching noise. To avoid this, siphon it out. You might have to add some water to get the siphon going strongly. You'll be able to suck up every last bit of gravel.

 

I was about to say the same thing, scoop then siphon.
As for the plants, they shouldn't suffer too much if you separate them, they will take a while to get back to their normal root structure, but it will happen.

 

ok so this morning i bought a bag of seachem fluorite black sand from LPS...not the onyx sand

started at 6pm...5 hours later, tank ripped down, plants and fish removed, old silica sand taken out, tank replanted, filter and fish back in

my back is SO sore...but it was worth it!

lets hope the tank stabilizes, prey for no mini cycle and all inhabitants survive!

will post pics of the tank with fluorite black sand shortly