Measuring parameters with algae

[Red2143]

If algae causes nitrate and phosphate to measure very low how do you know if water changes or other actions are effective without going to true zero and causing other issues?

 

[MoshJosh]

The only way to really know is to check your parameters. . .

That said, I'm not sure what you are asking? are you asking how you keep parameters from bottoming out in a system with refugium/algae reactor?

 

[Red2143]

From what I read you could have high phosphate and nitrates but measure zero because the algae consumes it. So if you do a water change to reduce and still measure zero how do you know how effective the water change was?

 

[MoshJosh]

If the algae has "absorbed" the nutrients, they are no longer in the water column. As long as you remove the algae (like in a refugium or reactor), or as long as the algae does not die and decompose, the nutrients will not return to the water column.

So I guess you could think of it as the nitrate and phosphate are in the algae but no longer effecting your water quality. If your tests say 0 (assuming they are reliable tests) then your nitrate and phosphate are 0. 0 is 0 regardless of algae or no algae.

 

[Red2143]

If the algae is absorbing all the nutrients how do I know how much gfo or similar to use without running the risk of bottoming everything out to a true zero?

 

[Jekyl]

Just don't ever let them bottom out. Manual algae removal, cuc, reduce white light, live phyto. All ways to combat algae

 

[Red2143]

Just don't ever let them bottom out. Manual algae removal, cuc, reduce white light, live phyto. All ways to combat algae

I see so something like chempure elite not a good idea at this stage?

 

[Miami Reef]

Playing with nutrients to control algae seems like a waste of effort.

I’ve seen more horrendous algae outbreaks in tanks with zero nutrients than in tanks with very high nutrients.

Think about the ocean, there are minimal nutrients, but without the herbivores, the reefs would be swamped with green.

You can control algae by getting herbivores that eat the type you have. It’s, oh, so much more effective.

 

[sixty_reefer]

If the algae is absorbing all the nutrients how do I know how much gfo or similar to use without running the risk of bottoming everything out to a true zero?

Our system never truly bottom out nitrogen and phosphorus, they just in many different forms that we cannot test with the equipment that we have available to us. For example in the nitrogen group nutrient start in the form of organic matter (fish food) and from there it’s broken down into many forms, the most abundant it’s ammonia that if solely used by chemotrophs (nitrifying bacteria) will become nitrite and nitrates just like during the nitrogen cycle. The reason you may not have a residual nitrate is due to those organic and inorganic forms of nitrogen being rapidly used by phototrophic organisms ( algae, coral, etc..) and heterotrophic organisms that will consume the organic compounds before they can release ammonia, in your situation I would say that most nitrogen is being used by photosynthetic organisms due to heterotrophic bacteria becoming limited by the depletion of nitrates or phosphates. In this situation there is no harm to dose nitrates or phosphates to the system, it’s actually beneficial and will slow down the algae growth.

here’s a simple sketch of the nitrogen path in our system