Is nutrient control an effective method of treating algae in a reef?

[mcarroll]

To me that sounds like CO2 is yet another "fertilizer" in that it can either be limiting or contribute toward health. In unbalanced situations, an increase can lead to problems. But if CO2 and nutrients scale up from ambient together, then no big deal....growth rates just scale with them. If I'm not mistaken, terrestrial plants work this way too.

I just know greenhouses and planted tanks get spiked with CO2 to drive faster growth, or to avoid CO2 limitation....don't know a lot more than that. For some reason we think differently in saltwater, but maybe we shouldn't?

 

[DesertReefT4r]

Since nutrients are a part of aquarium life we all have to deal with them. We apply several different methods to control nutrients. The goal is to find a balance in the system. While unwanted algae needs light and nutrients to grow and live so do corals not to mention we need to feed our fish as well. Keeping a reef tank at true 0 no3 and 0 po4 will cause corals to pale and slowly starve so we need to have some in the water for the corals. So now we have some no3 and po4 in the water for the corals but dont want algae and aglae like no3 and po4 too. How do we try to balance the system so we don't have our reefs over run with algae? Here are some tips. Go slow, dont do anything fast or right away. Slowly cook and cure your rock. Cycle the tank slowly, no fish, no lights, let the bacteria take over not algae. This prevents algae blooms during the cycle and lets the rock develop a bacterial coaring which help prevent algae growth on the rock. Use 0 tds rodi water 100% of the time, never use tap water. Have a fuge, give the algae a dedicated place to grow, start it up early in the tanks life and provide good lighting. Keep in mind the display lighting will compete with the fuge lighting to grow algae. Have lots of flow in the display. Most algae does better in lower flow. High flow also keeps waste from settling and let the tanks filteration remove it. Have a good method for nutrient control. Fliter socks, pads or floss are very effective at removing waste from the water, be sure to clean them 2 times a week or they start to add to the nutrient issues. Skimmers do an awesome job removing waste from the water. Fuges and ATS growing algae to be removed are highly effect. Solid and liquid carbon dosing methods to increase bacterial populations that consume no3 and po4. Media reactors for removing no3 and po4. Not over feeding. Lastly the good old water change, removing old dirty nutrient rich water with clean new water is a highly effect method of nutrient control as well as on of the simplest and in some cases most cost effective.

 

[Scrubber_steve]

I've not seen any data suggesting that corals grow better at lower pH.

"In line with this finding, the team discovered that cell and polyp sizes in the corals also increased with rising acidity."

Coral tricks for adapting to ocean acidification

 

[mcarroll]

"In line with this finding, the team discovered that cell and polyp sizes in the corals also increased with rising acidity."

Coral tricks for adapting to ocean acidification

Amazing

 

[Hans-Werner]

I think the polyp opening is also controlled by the (internal?) pH. At higher pH the coral polyps are more retracted and the zooxanthellae are shading each other while at lower pH the coral polyps are more open to expose their zooxanthellae to the light. You can test this very easily by using either sodium bicarbonate or carbonate together with calcium chloride. My impression is that corals at least don´t grow better at higher pH or even grow better at lower pH. The latter one can explained quite easily: The more exposed zooxanthellae photosynthesize better, transfer more energy to the coral host and this generates better growth.
Besides showing no better growth at higher pH they don´t look better with retracted polyps.

 

[taricha]

Just wanted to throw out the observation that in my system, if I run it without taking care to add nutrients, very rough estimates ...
Nitrate would become limiting in ~3 days (from 7ppm)
Phosphate would become limiting in ~2 weeks (from 0.10ppm)
Iron would become limiting in ~1 month (from a recommended Fe dose 0.10ppm)

Maybe other people's tanks are similar, maybe not.

 

[Subsea]

I think SPS are somewhat tolerant of lower nutrient levels but most other coral included LPS and softies not so much. My SPS colonies started to RTN from the base up pretty quickly after my phos was at undetectable for an extended period of time though the color was still great even while it was dying. I agree though consistency definitely helps.

As curator of Hawaii public Aquaria, Charles Delbrick said of the colors in a ULNS system,
“Looks like a reef on the verge of dying”.

 

[Subsea]

The Redfield Ratio of 116-16-1 is for phytoplankton. Macro algae “optimum ratio” is 560-30-1. I run mixed garden macro lagoons with high nutrients, but I don’t measure them.

Two 55G grow out tanks.