black gravel substrate

[Skittle]

I was thinking of getting black blasting sand for my goldfish but I'm worried about them eating it or not adjusting to it since they've been on gravel for like 5 years. Is there anything that is black and either really coarse or small in gravel size that I can buy without breaking the bank? Recommendations are welcome. Thank you!

 

[vetteguy53081]

I was thinking of getting black blasting sand for my goldfish but I'm worried about them eating it or not adjusting to it since they've been on gravel for like 5 years. Is there anything that is black and either really coarse or small in gravel size that I can buy without breaking the bank? Recommendations are welcome. Thank you!

I use this stuff but be aware some particles magnetic and will need to magnet algae cleaners