Capping an aquasoil, how?

Going to be perfectly blunt here: I've never done multiple substrates before. Never really got into aquascaping much when I kept fish as a kid. The recommendation I've read for the substrates I'm considering say that they will messy the water unless capped with a heavier substrate. So that leaves me with questions.
Would something like Black Diamond Blasting Sand be a good cap or should I look at something else?
How thick should the cap be?
Should this be on top of 2 inches of aquasoil or does the cap count toward substrate depth?
Is there any level of difficulty to capping an aquasoil that makes a bit of a mess in water?
Is there anything further I should know that I don't currently know enough to ask?

And I'm guessing the answer to this last one is yes but:
Would it be easier to drain the tank (is currently filled to test how well it was re-sealed) and apply the aquasoil and substrate then fill via hose?

Thank you all in advance for your help, it's greatly appreciated.

 

What aquasoils are you looking at none that I know need capping. Normal soil and potting mix will need capping

 

What aquasoils are you looking at none that I know need capping. Normal soil and potting mix will need capping

I've been looking at three:
Mr. Aqua Planted Substrate
Fluval Plant & Shrimp Stratum
Dannerle Scaper's Soil

I'm leaning toward Scaper's at the moment and from what I've read it's the least likely to muddy the water when being worked with.

 

None of those will need a cap and will do better without one. They might cloud your water when you furst fill it but it should settle in an hr or 2. Ive had the same aquasoil in my tank since I set it up yrs ago and its still good.

Yes it will probably be easier to drain the tank and just pour it in straight from the bag. Dont pre rinse it or anything else just dump it in and plant it before you fill it up with water.

Also some will leach a but of ammonia in the beginning which is good for the plants but no good for fish or inverts.

 

None of those will need a cap and will do better without one. They might cloud your water when you furst fill it but it should settle in an hr or 2. Ive had the same aquasoil in my tank since I set it up yrs ago and its still good.

Yes it will probably be easier to drain the tank and just pour it in straight from the bag. Dont pre rinse it or anything else just dump it in and plant it before you fill it up with water.

Also some will leach a but of ammonia in the beginning which is good for the plants but no good for fish or inverts.

Alright, thank you.

 

Just say: why people like to cap their subs.Maybe it floating all over place in tank like organic soil ,or want it to look more beautiful on their eyes like color of sand or small colorful gravel,or keep fert subs down to bottom lay to have it slowly release by time.
Some where in tank set up,people cap 1 lay powder fert then 1 lay subs then top up last lay yellow sand. When you top up, try to find color match the 2 so it less show out the mess while you replant,digging or steering the bottom.The rule of capping depend each people need but in general 1-1/2 inch subs and 1/2 inch sand Or small gravel .I do 1 inch each so it hold plant better.
Most the subs selling out there,best is not cap except organic soil subs.The look maybe too dark but best for later clean up And replace after 1-2 yrs end when subs become muddy..
Off line info: it also depend on what plants you will plant ( deep root or air root,floatting or tide in rock or wood) and how you want bottom look,they may use subs as only sand,only small gravel or just only shrimp subs or none shrimp subs,top up or none top up.Subs is just the lay to hold your plant at bottom so they can root out and grow.The fert in subs will not enough for your plant grow later ,so you will need fert add in ( liquid or root tap ) to make your plant grow properly.
Each kind of subs has pro and con.Do some info reseach to find out why you need that subs and how that subs help your tank...and what it help to...

 

Agree with above. I have a 75 gallon that I laid organic potting soil down, put some pea gravel on top of that and then capped with sand. The result is some really rich soil ( also sprinkled osmocote in it ) with a nice aesthetic that can be quite heavily planted.