Additional Substrate - Grain Size (etc) - Any Foreseeable Prob? [missing Posts]

Since replacing the fluorescent lightbulb recently, I've noticed that the substrate is comparatively brighter. Also, since building up the substrate recently in a vain effort to help my plant's growth, I've recently used up all of the original bag of sand. I'm thinking that the fish would probably appreciate a darker base so I might add some and gradually introduce more at each water change. Having had goldfish in the past who had a tendency to ingest their substrate with various adverse consequences, a change/addition of substrate is not a decision I would take lightly. However, Unipac limpopo sand is 1000-1200 grain size, in comparison with the 800-2000 grain size of the existing Unipac tana sand, so I don't foresee any difficulties as its grain sizes are in between. Does anyone else see any potential problems?
 

Thanks, Sue - helpful info.

@fishtales - irrespective of whether the Unipac Limpopo sand is re-formulated / definitely inert now, I'd advise you to stick to the play sand. I'm actually now wondering if the Unipac Tana Sand might possibly have been at least a contributing factor in pygmy cories not having done well in my tank - it definitely would be a lot sharper than playsand, as evidenced by the rather unsightly score marks on my tank where some grains came into contact with an algae magnet cleaner on the glass. On the basis of that possibility of its role in my cories' demise, the likelihood of the Unipac Limpopo sand being of similar consistency (if grain size is anything to go by), plus the issues your albinos have had already, I think it would be a safer idea for you to just use play sand.

Regarding uploading pictures, I can't get it to work directly on the forum either

I've usually found it fine but I think the particular photo I had taken had too much detail in it - as well as the sand, I'd actually wanted to show a plant I had that had survived for a whole week (some may be gasping open-mouthed in disbelief, and jaws may hit the floor that it's reached ten days old now) but its fine leaves may have provided too much detail to be under the necessary size for upload. Perhaps its non-upload is a blessing in disguise - if it had worked, I'd probably have jinxed the situation. Meanwhile, its plant-mate of the same age (a vallis) is succumbing fast to vallis melt. 

@fishtales glad you got your sand when I saw your post about DHL  it reminded me of when that happened to me and it was a painful experience.

I also use a tablet to view the forum and more importantly it’s an Apple device  so I have many issues uploading here, I downloaded Photoshop Express an app which will save the image as a PDF allowing me to upload pictures to a topic. 

Great to hear that you like the sand.
I hope we get to see some pics. 

Belly is healed, now hoping for some barbell improvement 

Good news, fingers crossed!

Excuse the steps to the side, I need them to get to the bottom of the tank for any alterations. Underneath the tank is never tidy

If you hadn't of said, we'd have never known! 

Nice looking tank, I've always wondered with backgrounds such as yours if they require any maintenance?

Looks great. 

[Some posts missing in this thread as, regrettably for us given that she was a valued member, former member Fishtales left the forum and deleted most of her posts.]