Feeding and Phosphates -- dilemma

[ScottB]

I agree with the previous posts linking cyano to low PO4 NO3. Yes, every tank is different, and the same tank is different at different ages.

I will offer the same advice that was given to me when my NO3 and PO4 were largely undetectable by RedSea and Hanna. It was simple, and allowed my acropora to color up (my goal at the time).

Start gradually increasing your feeding. Add another fish or two over the next month. Go slow. After a couple months if you're still low (<5 NO3 and <.03PO4) then put your skimmer and/or reactors on a timer and scale them back. Go slow. Test every 3-5 days. (You could reverse the order, but I would not do them all at the same time.)

I found this easier and more intuitive to accomplish than dosing Nitrate/PO4. Fewer moving parts.

 

[McGene]

Sounds like I need to experiment with feeding a bit heavier rather than starving the tank.
My nitrates are 0 and phosphates at .021.

 

[Belgian Anthias]

As much problems may be caused due to the supply of nutrients this can be linked to selective skimming. The solution may be found in decreasing the removal rate of the skimmer. Modern reefkeeping promotes LNS and VLNS without the use of biofilters and heavy skimming. It is known a skimmer is very selective in removing organics, TOC and DOC.

 

[TexasTodd]

Hoping not to derail as dovetails in.
What food has the highest N to P ratio? Meaning adds more N than P.

 

[McGene]

After discussing this with folks at my LFS I have decided to adjust my lighting schedule as a first step. I will vacuum tomorrow and adjust lighting and report back on this approach.
I'm not ready to embrace nitrate dosing just yet.
Thanks for all the discussion. I know it's hard to be definitive when you can't actually see the tank.

 

[saltyhog]

I've seen a little bit of cyano in every reef I've dived on.

 

[McGene]

Kinda reassuring

 

[Belgian Anthias]

After discussing this with folks at my LFS I have decided to adjust my lighting schedule as a first step. I will vacuum tomorrow and adjust lighting and report back on this approach.
I'm not ready to embrace nitrate dosing just yet.
Thanks for all the discussion. I know it's hard to be definitive when you can't actually see the tank.

Cyanos are sensitive for high light intensity. At daylight spectrum 320 μE m-2 s-1 PPF or 77 W/m²PAR will kill most cyano. But as they grow in microbial mats they may be covered by other organisms protecting themselves from the light. Just changing the light schedule will not change a thing as a lot of cyno's have a light and dark cycle and will adjust better to a light schedule change as will your corals. If you want to battle cyno's with light use a high intensity spotlight on the cyno for not more than one hour to prevent adaptation. They will die and release stored ammonia and phosphorus. But they will return.
A micro-bial mat is able to store a lot of nutrients and become self supporting provided with carbon and nitrogen by the cyano's.
Cyano's are able to do 5 celdivisions without any phosphorus present.
The best way to remove them is just vacuum them of and use a good effective UV for a period of time after cleaning. Do not let them develop microbial mats! Adjust the bio- balance and have a lot of patience. Solving a cyno-problem may take months. Do not search for a quick remedy, there isn't a good one. Adjusting a bit the removal rate of the skimmer may make a big difference.

 

[McGene]

Wow! Sounds like cyan is almost indestructible.....
Frankly, I wasn't too sure my lighting schedule was the culprit -- I only run 10K for a couple hours around noon and the remainder of the time the LEDs are programmed for the blue spectrum. I may still adjust the schedule, but it looks like vacuuming is going to be essential more often.
I really don't over feed (although some have suggested that I increase feeding since my nitrates are zero (at least as best I can tell from these crappy test kits) and phosphates are at .021 (using a very reliable Hanna digital meter).
Also, I do NOT plan to use Chemiclean again. It is not a long term solution and I don't want to put my tank through another chemical barge. I am running a UV, but, of course, it only works on the water that passed through it -- thus stirring my sand bed and getting the impurities into the water column will be needed (at least that's my thinking).
I've been away from the hobby for quite some time and it appears there's a new protocol for maintaining a balanced reef environment that I'm not knowledgeable of -- I'm still thinking old school.
Thanks for your patients with me.
Regards,
-gene

 

[Belgian Anthias]

Wow! Sounds like cyan is almost indestructible.....
Frankly, I wasn't too sure my lighting schedule was the culprit -- I only run 10K for a couple hours around noon and the remainder of the time the LEDs are programmed for the blue spectrum. I may still adjust the schedule, but it looks like vacuuming is going to be essential more often.
I really don't over feed (although some have suggested that I increase feeding since my nitrates are zero (at least as best I can tell from these crappy test kits) and phosphates are at .021 (using a very reliable Hanna digital meter).
Also, I do NOT plan to use Chemiclean again. It is not a long term solution and I don't want to put my tank through another chemical barge. I am running a UV, but, of course, it only works on the water that passed through it -- thus stirring my sand bed and getting the impurities into the water column will be needed (at least that's my thinking).
I've been away from the hobby for quite some time and it appears there's a new protocol for maintaining a balanced reef environment that I'm not knowledgeable of -- I'm still thinking old school.
Thanks for your patients with me.
Regards,
-gene

UV? How much µW-s/cm2 are you using? As you need high flow capability at least a HO UV-C germicidal lamp should be used or even better an Amalgam lamp. This is important as otherwise your UV will not kill cyano!

 

[McGene]

The UV I'm using came from BRS.
AUQA SHIELD UV STERILIZER DESKTOP
Specifications:
UV Lamp Wattage - 9 Watt
Wavelength - 250 - 255 nm (approx.)

 

[Belgian Anthias]

The UV I'm using came from BRS.
AUQA SHIELD UV STERILIZER DESKTOP
Specifications:
UV Lamp Wattage - 9 Watt
Wavelength - 250 - 255 nm (approx.)

The UV-C output of the lamp is needed in watt to calculate the µW-s/cm2, Not the power consumed by the lamp. Everything depends of the flow needed to sterilise all the water in a day which means a flow of the total volume/1h. I think this lamp will not be able to sterilise water at high flow. You need about 30 000 µw-s/cm² or 30mj/cm².

 

[Belgian Anthias]

UV-C 30mj/cm² is enough to kill most bacteria in clear seawater but this is not enough to sterilize the water. To prevent selective removal I prefer to use 180mj/cm² or 180 ooo µW-s/cm².

 

[Belgian Anthias]

Cyanos are sensitive for high light intensity. At daylight spectrum 320 μE m-2 s-1 PPF or 77 W/m²PAR will kill most cyano But *** they grow in microbial mats they may be covered by other organisms protecting themselves from the light. Just changing the light schedule will not change a thing as a lot of cyno's have a light and dark cycle and will adjust better to a light schedule change as will your corals. If you want to battle cyno's with light use a high intensity spotlight on the cyno for not more than one hour to prevent adaptation. They will die and release stored ammonia and phosphorus. But they will return.
A micro-bial mat is able to store a lot of nutrients and become self supporting provided with carbon and nitrogen by the cyano's.
Cyano's are able to do 5 celdivisions without any phosphorus present.
The best way to remove them is just vacuum them of and use a good effective UV for a period of time after cleaning. Do not let them develop microbial mats! Adjust the bio- balance and have a lot of patience. Solving a cyno-problem may take months. Do not search for a quick remedy, there isn't a good one. Adjusting a bit the removal rate of the skimmer may make a big difference.

Using a strong spotlight, intensive light, makes it possible to know if you are really dealing with cyano. If after one treatment of one hour the day after nothing has changed You may be dealing with Yellow-green algae, Coccoliths, Diatoms and or Dinoflagellates as they are able, and most plants, to protect there cells by transforming the light energy into warmth, called the xanthophyll cycle. Cyano's do not have this ability. Microbial mats can maintain many non photo-synthesisers and they do not necessarily have to contain cyano's.