Corals not growing, pest algae growing great

[ThunderGoose]

My tank is 10.5 months old now. I'm doing great with fishes, pretty good with invertebrates and mediocre to bad with corals. I'd like some advice.

The tank is 55 gallon with a ~ 10 gallon sump that I have set up as a refugium with grape macroalgae (probably Caulerpa racemosa), live rocks and problem critters (read: crabs). I am currently dosing calcium and alkalinity using a pump and magnesium by hand about once a week on an as needed basis.

Salinity is 1.025
Temperature is 78
pH is 7.85
Ammonia, nitrite and nitrate are all 0
Alkalinity (KH) is 9.4
Calcium is 369
Magnesium is 1200
Phosphate is 0.052

[I have never had my nitrate read anything but 0 since the original cycle]

Stocking: I'm probably a bit overstocked with fish and I have a very, very large BTA plus lots of invertebrates. I feed with what I think is a heavy hand. I was dosing micronutrients or phytoplankton and broadcast feeding corals regularly until I got a major cyanobacteria bloom. I've cut that and cut back on feeding to try and deal with the cyanobacteria (still a problem). I have to clean the glass at least every other day for regular algae and I have a healthy growth of coralline algae on the back glass.

No skimmer but I've been doing 5 gallon/week water changes with Instant Ocean Reef. I do have an RO/DI unit. My refugium runs opposite the tank for oxygenation/ pH control.

Lighting is two Radion XR15W G4 Pros, color mix is based on coral lab LPS/Soft template, starts at 12 with a 2 hour ramp up to 55%; run at 55% for 7 hours; 1 hour ramp down to blues.

I'm starting with soft corals and LPS. I've lost a few and the others are not growing or are just limping along.

What should I be doing differently? change the pH? Change the salt mix (it's the only brand available close to home)? Not change the water as often? Target feed? Switch to the Triton method? Pull the live rock out of the refugium and replace with Caulerpa?

I do have access to the ocean if ocean water would be better (although I live in New England and I'm not keen on the idea of collecting during winter.

Right now it seems like the pest algae is outcompeting the corals for nutrients. I'm happy with the fish and invertebrates but frustrated with the corals. I welcome any and all suggestions.

Thanks!

 

[A Toadstool Leather]

Calcium and magnesium are a bit low. What did you use to test phosphate. Btw your nitrates are at 0 since the algae is consuming it.

 

[A Toadstool Leather]

Also dont bother chasing pH. You cant really do much about it due indoor CO2. As long as alk, ca, and mg are good the corals should do well.

 

[alten78]

Unless I missed it, what do you have growing in the refugium? Why no skimmer? We all see the posts about no water change or no skimmer tanks that do well, but they all seem to make up nutrient export in another way.

You definitely have too much nutrients in the water hence the cyano and lack of growth. Heavy import and light export spells disaster (as you are seeing.)

 

[Animal Chin]

First, a picture of your tank would help so we can see the coral and what state they're in and how many you have.

Instant ocean is fine, I've used it forever and it should be fine for your tank. You may not need to be dosing though if you don't have much coral.

I can't think your phosphate or nitrate numbers are accurate for a few reasons. First cyano loves phosphate, second you say you feed a heavy stocked 55 often and third you have no skimmer so no bio waste is being removed before it breaks down.

How much algae is in your tank?

5 gallons a week on a 55 gallon is not too much of a water change at all.

Without seeing what you have and really seeing the issues, I'd suggest a good skimmer, 10 gallons a week water change, no more dosing of cal/alk as they may just be calcifying somewhere else if they are not becoming coral and see if all that helps.

 

[Animal Chin]

oh and stop feeding your coral for now, let those radions feed them. You're probably just adding nutrients to the water that don't really need to be there right now.

 

[PatW]

Like the others above, I believe that you have a nutrient problem. Whenever I get algae, it is always traceable back to having too high a phosphate level. You can measure the phosphates, but they can be 0 even with the Hanna ULR because the algae are sucking them out of the water as fast as you are adding them.

Here are some ways to lower nutrients:

Run GFO, granular ferric oxide, in a reactor.
Large, frequent water changes.
Running a protein skimmer.
Running an over sized protein skimmer and dosing carbon.
Running filter socks and cleaning them every twice a week.
Cleaning the glass, rocks and sand at least once per week.
Running macro algae in a refugium.
Running an algae scrubber.
Don’t feed so much.
Don’t feed so much ( yeah like we listen to this one ).

Also your calcium and magnesium levels could stand a boost.

But if you have a flourishing anemone, you are doing a lot of things right.

 

[JOKER]

Nitrate and phosphate also is out of balance. With that level of phosphate nitrate shouldn't be 0 IME. I never feed my coral, I let the fish and light do that.

 

[lou dog420]

Flow??

 

[lou dog420]

I am no expert by any means, but in my opinion flow is one of the biggest factors to having healthy thriving corals. Second only to water chemistry.

 

[ThunderGoose]

Since you asked for flow: I have two CoralBox QP5 (not thrilled with these, they're set for variable flow but they quit adjusting after a couple months) and my return pump is a Sicce Syncra that puts out 714 gph

Images of my tank

Don't let the big corals deceive you - I bought the big ones recently. The sand is not really that white, I haven't learned to balance the colors quite right in my photos.

Zoa rock

Toadstool has not grown

These mushrooms are some of the first corals I bought. The red one died.

 

[lou dog420]

How long has the tank been up?

 

[lou dog420]

Honestly your corals look fine to me, just be patient. My system really seemed to take off at about 12 months.

 

[Michael Paschke]

As I've only been back in hobby for 2 months after many, many years away - I defer to the advice I read above, which has helped me with an algae bloom.

However I did want to comment on what a beautiful tank that is! Looks like things are going well to me

 

[slayerhellfire]

isn't that high for Phosphates or I am missing somthing???

 

[Cory]

You cant have 0 no3 and 0 po4 and expect coral to grow. Id try to increase them.

 

[reefndude]

I'm not seeing much of an algae problem. Corals look good

 

[THX1138CY]

Are you using the API test kit for Nitrates? I am super skeptical of 0/0/0 reports after my own run in with not shaking the #2 Nitrate reagent bottle for 2 minutes prior to testing, found out the hard way I had a nitrate issue. I was having similar issues to what you are reporting, lack of coral growth, some died, turned out I was improperly using the API Nitrate reagents and getting a false 0 result, upon correction, my Nitrates were off the chart >160 ppm, had to do a series of 30% water changes, one a day, over a week just to get it to 20 ppm. I was losing a turbo snail a week prior to the water changes, zero snail losses after that. Shrimp/Anemone/Fish didnt care about the Nitrate level, just the snails and corals.