Need help with my SPS

[AgeDynasty]

Hello I have a problem with polyp extension. I just don't get any I think I may have to much flow.

Tank Info:
75 gallon
29 gallon sump
8 bulb t5 fixture
2 hydro krollia 1400
1 MP40 set on about 40% on pulse
Calcium is 460
Alk is 8
Nitrate 0
Nitrite 0
Ammonia 0
PH is 8.3
Specific Gravity is 1.027

 

[stikhead]

How is your coloration and growth

 

[AgeDynasty]

Color is good growth is slow

 

[Ink]

How do You test nitrates? If the value is correct, they could be too low.

Posting some pictures will also help to clarify the situation.

Luca

 

[AgeDynasty]

I use API Test Kits I know they are not the best

 

[Southreef]

You could very well have too much flow. It's really tough to say whether or not you do without actually seeing your tank in person. The amount of output you need from your MP40 depends on a lot of things like aquascape and the size of the colonies in your tank. I recently had a tank crash on my 90 gallon and subsequently lost a lot of larger colonies. Before the crash my two MP40's were set at 60% in master/slave on nutrient transport mode. After the tank restart, I have only small frags in the tank and I also removed almost 40 pounds of live rock. I had to dial my MP40's back to 30-40% to not crush the polyps on my sps with all of that flow.

Try it out, turn your flow down for half a day and see what happens.

I just noticed that you are running an 8 bulb setup over a 75... what is your photo period? I run 6 bulb ATI with actinics only for 11.5 hours and all six bulbs (100%) for 5 hours a day.

What is your PO4? Like Luca said, an actual ZERO on nitrates isn't totally ideal. Personally, I have been dosing Potassium Nitrate to keep my nitrates at .25-1PPM with better results than zero NO3.

 

[AgeDynasty]

I just tested using the API test kit and it read zero. I attached the oic of the tank

 

[Southreef]

Ok... the API phosphate tests are unfortunately a little less then accurate. Looks like you have a lot of open areas in your tank so I would recommend the following:

1) Try reducing the flow and perhaps even taking out one of the powerheads on the left... this is the easiest thing for you to do and sometimes the simplest things are the answer. One thing I didn't mention before is the fact that you also have to factor in your return pump's flow into your total tank turnover.

2) Look at your source of top off water and saltwater makeup very closely. Are you using your own RO/DI? What is the TDS of the output?

3) While you're busy doing those two, order or borrow someone's Hannah Phosphate tester so you can get a more accurate reading of your PO4.
a. While on the topic of testing, consider getting Salifert testing kits for your tank's other parameters. They are worth the money in the sense that they give more accurate results than the API

4) Once you determine the water coming into the tank via top-off and water changes is of acceptable quality: What is your water change schedule? Could you do more frequent water changes?

5) What is your bio-load like? Assuming the API tests are accurate, you have no nutrients in the tank which isn't good for general coral health. Consider feeding your fish more frequently or even adding a couple of fish...

6) Do you have pests like red bugs or acropora eating flatworms?? These can be very difficult to detect. Get a magnifying glass or macro camera and take a close look at your SPS.

7) Analyze your lighting schedule and consider reducing the amount of time you have the lights on full blast.



This is how I have tackled issues in the past(with the help of fellow RCers). The key is to try to only make one change at a time and wait to see if you get results. This being said, it could be a while before you see results on one of the steps above... patience and perserverance is key.

 

[SGT_York]

The API tests are accurate but they are not in the correct scale. 0 - .25 on the phosphates alone when you start seeing color you are already outside the safe parameters for stony corals. So you test says zero but your coral are still in the danger zone.

Get better test kits so you know that your water quality is acceptable. The calcium and alkalinity tests are just fine.

 

[AgeDynasty]

What about Red Sea test kits

 

[CHSUB]

hobby grade test kits are not accurate enough to give readings that approach 0.00. if you have fish and you feed them there is enough po4 and no3 for your sps'. to much flow is more likely.