Will emerald crabs eating bubble algae increase nutrients?

[zaddy]

Let’s say there’s a lot of valonia / bubble algae proliferating in your tank, and you were to add an army of emerald crabs to eat them. by how much will the consumption of the algae by the crabs affect nutrients (po4/no3)? After all, algae itself is a manifestation of nutrients, and those nutrients won’t just disappear but rather will added to the water column right? Appreciate any ideas / experiences with this.

 

[blaxsun]

Probably negligible.

 

[liddojunior]

Biology isn’t perfectly efficient! The waste made by crabs aren’t the same value as what they consumed. So the algae reduces your waste nutrients and they get turned to growth, and the crabs then eat that and it turns to growth for them.
Waste made by the crab will be less than what it took to grow the algae.

With that said, the reason you have an algae outbreak means something is really off balance and prompting algae growth. You’ll get another Algae to take its place or the bubble Algae won’t really go away.

The solution isn’t an army of emerald crabs. You should manually remove them and use a couple crabs to help prevent growth of new bubbles. The large bubbles they won’t eat instead they will pop them and you’ll have even more.

 

[Lasse]

Cold blooded species convert around 20 - 25 % of the eating resources into biomass - it means that around 80 - 75 of the bounded nutrients going back to the water - taken up of new algae and after the new algae have been eaten - 80 - 75 of the new bounded nutrients going back - it means that the nutrient you now have bounded in bubble algae will slowly be converted into emerald crab flesh.

IMO - you should introduce some emerald crabs in the beginning and see if that amount will decrease your bubble algae - if they not decrease them to zero - introduce some more - or just wait. Emerald crab eats much more types of algae - you will probably not get any other algae problem

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

In short, anything eating almost anything will increase nutrients to some extent.

 

[Lasse]

In short, anything eating almost anything will increase nutrients to some extent.

Yes - but IMO - there is a difference between if it is external given food or internal produced food. In the first case - if no biomass is taken out - it will increase the total P load in the system (in waste as PO4 in the water, in metal bounded PO4 and P in biomass)

In the second case (only internal produced food) it will in the long run reduce the waste (PO4 in the water column) decrease the stored PO4 (metal bounded PO4 in rocks and sand) raise the P in biomass and move it between different organisms in small loops

A normal aquarium depends both of external and internal produced food - it will be a combination between the two extremes - IMO.

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

Yes - but IMO - there is a difference between if it is external given food or internal produced food. In the first case - if no biomass is taken out - it will increase the total P load in the system (in waste as PO4 in the water, in metal bounded PO4 and P in biomass)

In the second case (only internal produced food) it will in the long run reduce the waste (PO4 in the water column) decrease the stored PO4 (metal bounded PO4 in rocks and sand) raise the P in biomass and move it between different organisms in small loops

A normal aquarium depends both of external and internal produced food - it will be a combination between the two extremes - IMO.

Sincerely Lasse

That's certainly true.