Sump Live Rock ...Why?

[Randy Holmes-Farley]

IMO, since bacteria growth is related to what it has to feed on, as long as it has places to grow, that the exact amount of rock isn't that important. 0.5 pound per gallon to 1.5 pounds per gallon probably has about the same effect.

(unless we start talking about hiding spots, breeding spots, coral placement, ect)

When dosing organic carbon, some folks get the bacteria growing in the display, which is rather unattractive.

Having enough other places for it to grow, and dosing directly into those places can potentially make the difference. Whether this the whole reason or not, I've never seen bacteria growing on surfaces in my display even at doses so high the water was becoming hazy with bacteria.

 

[Reefin' Dude]

if surface area was important for bacterial growth, then how/why does carbon dosing work?

how are the bacteria in the water column different from the bacteria in the LR?

how does this info play into this?

bacteria will grow anywhere where there is food, but will not grow where there is plenty of space. which is limiting?

G~

G~

 

[Randy Holmes-Farley]

if surface area was important for bacterial growth, then how/why does carbon dosing work?

how are the bacteria in the water column different from the bacteria in the LR?

how does this info play into this?

bacteria will grow anywhere where there is food, but will not grow where there is plenty of space. which is limiting?

G~

G~

Yes, bacteria can be organic carbon limited, but in the absence of appropriate surface area, they may end up growing visibly in the display tank, or suspended in the water, causing milky looking water.

Also, if you are trying to promote bacterial consumption of nitrate in low O2 regions, it is clear that space is the limiting factor in many tanks, and that is why adding things like a deep sand bed can work.

 

[Reefin' Dude]

but what if what we are told about how the nitrogen cycle is not exactly the way we have been told in the aquarium literature?

i have seen plenty of water column bacterial blooms in tanks with plenty of LR/sand/whatever the added surface area of choice is. if the water column is full of nutrients, then the bacteria will have at them and replicate to take advantage of them. the bacterial blooms go away once the food source has gone.

am i allowed to link to information form other forums and aquarium sites here?

G~

 

[xxstephensxx]

I like the fact that I can put less in the DT.

 

[HV1990]

I have Live rock in my sump however I have a maxijet pump as a powerhead to keep the water moving. Thus keeping the detritus suspended. The maxi isn't anchored in any way and when I move it for whatever reason it changes the current locations.

 

[heritage]

if surface area was important for bacterial growth, then how/why does carbon dosing work?

how are the bacteria in the water column different from the bacteria in the LR?

how does this info play into this?

bacteria will grow anywhere where there is food, but will not grow where there is plenty of space. which is limiting?

G~

G~

I don't think space is limiting. Carbon is the limiting factor. Carbon dosing works because as the bacteria ramp up and consume nitrates and phosphates they are skimmed out along with the nutrients they consume. They will out compete algae for the same nutrients.

Autorophic bacteria are capable of synthesizing its own food from inorganic substances, using light or chemical energy. Our beneficial filter bacteria are autotrophs.

Heterotophic Bacteria cannot synthesize its own food and is dependent on complex organic substances for nutrition. The heterotrophs in our aquariums mineralise the organic waste (break down the uneaten food, fish waste into ammonia). These are what's responsible for bacterial blooms. While it won't have a direct impact on any of the animals we keep ( save fish) they use huge amounts of oxygen, this is why its important to keep the water well oxygenated.

Merely doing water changes will have little effect on this (they are capable of reproducing every 20minutes ) which is why its important to siphon or remove as much detrius or organic waste as possible.

 

[Randy Holmes-Farley]

I don't think space is limiting. Carbon is the limiting factor. Carbon dosing works because as the bacteria ramp up and consume nitrates and phosphates they are skimmed out along with the nutrients they consume. They will out compete algae for the same nutrients.

.

I think hypoxic space is limiting in many cases, or else deep sand beds would provide no useful function in any aquarium, and certainly some folks find that they do serve to lower nitrate in their systems.

 

[heritage]

I think hypoxic space is limiting in many cases, or else deep sand beds would provide no useful function in any aquarium, and certainly some folks find that they do serve to lower nitrate in their systems.

Lol... That's a debate that will go on forever. :lmao:

But for me, I don't treat my sand bed as if it was serving any kind of biological function. It's ornamental and it gets cleaned once a week.

 

[Randy Holmes-Farley]

I agree that mine were too, and I no longer use them, but plenty of people have had different experiences. Maybe they had more organic matter than you do.

 

[heritage]

Probably... I do my best to remove as much as I can, but to be honest, its getting old....hmmm.... I think I see a bare bottom tank in my future. :thumbsup: