substrate conversion

[cowfish7]

I have a 10gal running with gravel substrate.
Got some black diamond (blasting) sand washed.
First problem is that there is a very small percentage of greenish/grey particles in the sand. Washed for a looooooong time and have not been able to get it all out. Does not look great because it settles on the top surface, but I mixed it in to look better. Hopefully it is nothing detrimental, other than appearance.

I planned to put the existing fish into a bucket while I removed the gravel installed the sand. I am using only a sponge filter on the tank and do not have access to a canister.
Now I am starting to wonder if I have to wait more than a few hours for the tank to settle before returning the fish. I did a small test tank (2gal) and without aeration it seemed like it was just a few hours (or less, forgot to watch the clock) before it settled.

Is there anything else that needs to stabilize, other than the sand to settle?
I expect a bit of an issue with the loss of BB, but am hoping it would be OK to put the fish back in after a few hours. I have 4 bloodfin tetras.

 

[Mebbid]

I hate to say it but if you're seeing dust and particles then you will probably need some more aggressive washing. A hose works best for the black diamond sand. Also, be sure that there is no sheen on the surface of the water when you add water as there is a little bit of an oily film on the blasting sand.

 

[cowfish7]

Yes, I used the hose for what I thought was a long time (after having rinsed a lot before that, too), and there is definitely no oily sheen anymore. Still not entirely sure it is rinsed enough, though...

to clarify: the green/grey particles settle on the surface of the black sand, not floating in/on the water . I can mix them back in, although they are obviously less dense than the black ones.

 

[NYgiantsRP]

Just give it some time. It will all settle. The fish should be fine. They live in sandy water in the wild. I don't think a few particles in your tank will hurt.

 

[Mebbid]

Just give it some time. It will all settle. The fish should be fine. They live in sandy water in the wild. I don't think a few particles in your tank will hurt.

Sand would be fine. The black diamond blasting sand is quite a bit different though.

How much "less dense" are we talking about here?

 

[NYgiantsRP]

What's so different? What would hurt the fish?

 

[cowfish7]

Sand would be fine. The black diamond blasting sand is quite a bit different though.

How much "less dense" are we talking about here?

If I agitate the sand (i.e. during washing), it's what mixes into the water column, then settles onto the surface of the substrate. I've done a test, using it on a small tank, and the water is just a little cloudy (more cloudy at the substrate level), but I think the general cloudiness is actually kinda normal for a newly filled tank? It just never looks 'crystal' right away. Get it running with fish and a filter and it looks better.

I am going to run a sponge filter on this tank, so I guess it won't get much agitation (i.e. no airstone). Really wish I had a canister, that would probably clean it right up.

I guess my real question is for anyone who has used the blasting sand and found the same material and gone ahead with the build without issue. I am wanting to put my fish back in, asap, once I start this.