rocks

[Pufftastic]

Limestone is not the best choice. Unless you like a thick layer of crust on your tank.

I've never had a problem with that, and have been using Texas holey rock (although only in FW tanks) for years. No crust here!

[bertie 83]

ok now i defo need rtr to chime in i am so confused. i will fashion a light which puts rtr in the sky and i am sure he will appear to look over this. and then i will know lol

[Lil' Swimz$]

You could say its really matter of personal preference. I don't like have something in my tank that will slowly, but definitely, harden the water. My water is already has hard as rock.

So it must be preference?

[bertie 83]

would like to know more about this f/w rock to aid filtration lol still want a variety tho. thanks swims i am also in a hard water area

[RTR]

For FW I want only inert rocks, without metallic mineral veins. Limestone would only be for Rift Lake or other alkaline water fish, and I still prefer inert. I acyially use mostly slate or river-smoothed rocks.I do not want anything that will affect the water parameters.

For SW you have more choices and the limestone and coral rock are great.

[bertie 83]

so porous rock building up bacteria colonies a bonus? or should i just get what looks nice. may sound like a stupid question but how beneficial etc etc

[sevenyearnight]

I think you should get whatever you think looks nice in freshwater, I'd gather that most of your biological filtration will be rich where the water flows, and probably the added benefit of the rocks' porosity wouldn't weigh heavily enough to get rocks that you might like less, perhaps?

[bertie 83]

i always run massive biological filtration,but.....can you ever have enough? i dont believe so. so if porous rocks will aid i would sacrifice what i think looks nice, if that makes sence. no matter how much a man has......he would give it all for a little more lol

[sevenyearnight]

I think unless you put the rocks in your filter, it doesn't matter.

[RTR]

Warning: Biology-speak may cause headaches!

Biofiltration is input-limited. The FW biofiltrtion is ammonia to nitrite to nitrate only and period. There is no such thing as masive biofiltration without a massive bioload on the the system. The two different bacterial types involved grow to match their food (energy, actually) and stop. The individual cells are not permanent, They do divide and some lose their attachment and die if they cannot reattach within a reasonable time. This means that the maximum bacterial component is 2x the minimum required number, but it cannot hold at that level - If the usual ammonia production is 1x, the 2x colony size will die back. This is basic bacterial growth and population kinetics. If the ammonia level doubles over time, the colony size expands to handle that new load.

When you fishless cycle, the 2-3ppm ammonia level used late in the process is at least 2x the expected total ammonia production per 24 hours of the tank fully stocked.

In SW the situation is quite different when LR is used. (FOWLR plus skimmer and macroalgae refugium) there will be surface and shallow crevasse aerobic bacteria doing ammonia to nitrite to nitrate just as in FW biofilters, but there will also be significant colonies deep in pores in the rocks doing anaerobic denitrification such that the sort of nitrate titers we see in FW just do not happen. - the nitrate is reduced to nitrogen gas and off-gases from the tank if the nitrate itself is not used by the microbes and algae. Plus lots of other bacterial and algal types are operating on other pollutants. as with heavily p\anted tanks in FW. There is many-fold the pollution-devouring potential in well operated SW tanks as we can do easily in FW. We can come fairly close with careful planting and reverse light cycle veggie filters, but is not as easy and generally still required large regular partial water changes).

But the functional load of pollutants is always just matched or temporarily slightly exceeded by the bugs and algae consuming them. We cannot stockpile excess bugs beyond what the tank generated to feed them.

The above is heavy going I know, but if you think about it. Biological processes tend to rely on input.