crushed coral/agagonatrite substrates

[suzie-q]

question: right now i have natural stones on the floor of the aquarium someone suggested i use crushed coral or agonaite , can i add this on top of the stones? i know i have a lot of probably uninformed questions but i am asking the experts for advice just want to keep my puffers alive and swimming they are cheesepuff and powderpuff both are figure 8 puffers i have them in a new tank and they are adjusting, i have to get the liquid test kits as suggested because of accuracy, i have been feeding them shrimp, bloodworms, crab, was thinking about adding some live java ferns to the tank is that ok to add these plants? thank-you all for your help and suggestions which are most welcome suzie-q

[RTR]

Aragonite or crushed coral will be finer grained, so will sink to the bottom, leaving the stones exposed to the water - which will not help the alkalinity/carbomate hardness nearly a much. You do not need much substrate depth - a half inch to an inch of the other substrates is all you really need. Save the iert stones for other use.

F-8s especially need good alkalinity, as the low specific gravity they need does not really provide as much as they like. These are among the long-lived puffers - IF they are kept under the best conditions.

I have never kept java fern in brackish water, so cannot offer any suggestions there.

[Iliveinazoo]

A java fern will do fine, I have one growing nicely in my Figure 8 puffer tank at SG1.003 at 25degC along with many other plants. Check out this post for other plants that will do well in brackish water:
viewtopic.php?f=8&t=4792