I asked on another forum if there was a darker substrate that has the same buffering capabilities as coral sand.I was told that it is a myth that coral sand buffers the water and that if i added a commercial buffer to the water i could use any substrate that i wished.Is this true ?
It's a bit more complicated than that. Coral sand does buffer water but it does so slowly and to a limit and would never be used as the sole kH buffering system in a tank, especially where the level you need is considerably higher than the level in your supply. It's more usually used in combination with other carbonate buffers such as limestone rock and so on. Commercial buffers still need to be added to any water gong into the tank as all these soluble substrates and rocks take time to buffer the water. As soon as you remove any of the buffered water and replace it with fresh water that hasn't been buffered, the gH, kH and pH in the tank will drop, gradually rising again until the next water change.
If you are keeping fish who are in need of hard alkaline water and are also very sensitive to nitrates and organic waste (like Tangs), you'll need to be doing frequent partial water changes to keep conditions healthy. If your tap water is a long way below the required hardness and alkalinity needed for the fish, you will need a large amount of commercial buffer (or home made buffering powder) in every water change to match the kH, gH and pH to the levels needed in the tank. Buffers like coral sand and limestone can help prevent kH and pH from dropping between water changes and where the change needed is minimal, can buffer a lightly stocked tank using only a small amount of additives in fresh water.
If you choose to, you can skip the decorative buffers and do the whole job with commercial or home made buffers with the following caveats:
1) Tank must not be overstocked 2) Water changes must be done religiously at least once a week and more often if nitrates rise faster 3) Buffers must always be used in every water change and in quantities high enough to maintain a stable and suitable ph, kH and gH level over the time between water changes.
No not that I know of. I don't use ant buffering decor in my Tang tank though and I use RO so remineralise and bufer the water instead. The one thing I o to help in the tank is keep a bag of oyster shell in the filter. But in the main I rely on making sure I change water often enough to avoid any drop in pH between changes - keeping nitrates down in a small tank requires that anyway.
I use a fine black inert gravel in my Tang tank as I agree with you that dark substrates show up the fish better. As long as you keep up the water changes and maintain the buffers it's not a problem. It just means you've no room to manoeuvre and can't skip a change if you've got the 'flu or something like that
What is that sand you have in the photos Fishlady? Looks really cool! I do a 20% waterchange every friday after feeding and then have a fast day on the saturday to help keep nitrates down.Waterchanges aren't a chore for me.I love the way the fish come alive after a bit of fresh water is added.I'm getting a Aqua One Aquanto 182 for christmas.Really nice looking 4 footer.I had a Roma 240 a while back but always thought it looked too deep.The aqua One is 18 inches deep,4 less than the Roma.I'll be sacrificing about 60l in volume but as long as i don't overstock and keep on top of my waterchanges i'm happy to do so as i think this tank will suite the low ceilings we have in our living room better. I'll be transfering my multi's in there on their own for a bit so they can increase the colony in peace,then i will introduce a small group of young comps.(my favourite looking fish),so to keep the multi numbers down.