How About This

Xraymark · Nov 21, 2011

Once fishless cycle complete and before I add fish I want change my substrate to sand.(new tank)

At moment I have in Tetra complete substrate mixed with Aquagrit. On top of this I have black gravel. The plan is when I do my large water change at the end of the cycle to take as much of the gravel as possible out without disturbing the soil below. I suspect some gravel will be left. Then add black sand on top.

Are there any issues with this?

Also should I do another qualifing week before adding fish as some bacteria may be lost or just rely on the filter.

Cheers

mike455555 · Nov 21, 2011

why not drain your tank into a bath or something? change the substrate put half the water back in. as some substrates turn the water cloudy when disturbed

Xraymark · Nov 21, 2011

I want to keep my soil and aquagrit to keep costs down.

So i'm only trying to replace the gravel. Also this way I thought it might be less of a mess.

mike455555 · Nov 21, 2011

why not drain it and like scoop it out?

to be honest i doubt it would matter how you did it, both ways would work

as for the bacteria in the filter id measure it for like 2 days (still dosing) if there's an increase don't add fish if there's not do =]

soybean · Nov 21, 2011

If you add sand on top of the other substrate it will likely eventually mix together.

Xraymark · Nov 21, 2011

As in mix with the soil?

My hope is that a good layer of sand will stay on top. Hmmmm, should I just get rid of everything in the tank and replace with sand. Which leads me to the question is that okay for plants.

Also is 25kg of sand(trilcot black) enough for a rio 180? I think the dimensions are 101 x 41cm(floor plan).

soybean · Nov 21, 2011

It's entirely up to you but I personally got rid of everything - expensive plant substrate included - when I switched to sand. There were a few bits of gravel left at the bottom I couldn't be be bothered to pick out - even these are coming to the surface as the sand settles.

You can always add root tabs and liquid ferts.

However, if you do a thick enough layer over the plant substrate, and you don't have bottom feeders like corys, it may stay separate for a little longer, especially if the plant substrate is quite compact. But I think too much substrate takes up unnecessary swimming room.

I used about 15kg of playsand in my rio 180, although it's not a very deep layer and I will be topping it up with the remainder of one of the bags, bringing it up to 20kg - I think 25kg would be more than enough.

eaglesaquarium · Nov 21, 2011

Planting in just sand is fine for plants. You can add ferts in tab form near the roots, or just to the water column. The plants will be fine.

As far as removing just the gravel, why not scoop out the substrate into a colander or strainer (new of course). The gravel would be caught, while the smaller, finer things would fall through. Sand on top of the finer material would take a while to integrate. Putting sand on top of gravel would result in the sand falling between the small rocks and the gravel would be visible quickly. The same is not true with finer media substrates. The finer your base, the more likely the sand will remain on the top. If you continually stir up the substrate during water changes though, the sand will fall through more and more.

If I were you, I'd remove the gravel as much by hand (scooping) and just replace with sand on top.