Very low nutrients buy SPS progressively browning - Please help me trouble shoot

[Punchanello]

I have a 5x2x2 litre system bare-bottom with an ATI 4 x 80w Hybrid Powermodule lighting and 2 x Tunze 6105s. I'm running chaeto under a grow light and a skimmer and that's about it. System has een up over 12 months and is currently fallow (ich). Most of my sps, once settled are growing. Not sure it's considered fast growth but I'm new to this so happy with that. Here are my parameters -

7.7-8 ppm dKH
450 cal
1400 mg
Nitrates and phosphates undetectable or nearly undetectable with Salifert test kits

My problem is that most of my SPS (not all) seem to be getting browner. This started well before I went fallow 8 weeks ago but has continued since and possibly got worse. Even before I went fallow I had a low bio-load. My understanding of the theory is that it could be due to low light or high nutrients increasing the amount of zooxanthelae in the tissue causing the brown look. I don't think I have either of these issues. In fact, I'm struggling to keep any nitrates or phosphates despite heavy ghost feeding and I have a lot of light between the LED clusters and T5 happening.

Clearly my corals are stressed, but I can't figure it out. Happy to answer any questions if it can help me troubleshoot.

This was the tank about 6 weeks ago (have removed sand since).

 

[brett.sizeland]

It could be from a lack of nutrients. I had something similar happen where I lost a lot of colour and even some colonies because I had a lot of nuisance algae outbreak in my frag tank that is linked to my main display and consumed all the available nutrients.

I would remove the chaeto as there is no real load at the moment with no fish. Continue feeding and try to get the N03 and P04 to start to register on the tests and see if you get any improvement.

What are you using to feed the coral at the moment?

 

[Durandal]

I always struggle to keep SPS in fish free tanks. Adding more invertebrate bio-load wseems to help, anything that you can get to eat large amounts of meaty foods should secrete out unused nutrients just like fish.

good luck!

 

[ReefAddict16]

Lower the height of your lights. I’m running my 6 bulb 4” above the water line. How high do you have them and what bulbs are you using?

 

[Durandal]

I LOVE my par meter, some of the best money I ever spent in this hobby. Dead/bleached/browned out corals are money down the drain.

 

[29bonsaireef]

Lower the height of your lights. I’m running my 6 bulb 4” above the water line. How high do you have them and what bulbs are you using?

I agree with this, how high are your lights? My N03/P04 are very low, can't get a reading for either. I have the 8x80w sunpower and keep it about 8-9 inches above the water. I do however, have fish, and I feed them a few times a day. PAR meters can work wonders.

 

[Punchanello]

It could be from a lack of nutrients. I had something similar happen where I lost a lot of colour and even some colonies because I had a lot of nuisance algae outbreak in my frag tank that is linked to my main display and consumed all the available nutrients.

I would remove the chaeto as there is no real load at the moment with no fish. Continue feeding and try to get the N03 and P04 to start to register on the tests and see if you get any improvement.

What are you using to feed the coral at the moment?

A mix of blended clams, shrimp, Nori and Reef roids

 

[Punchanello]

Lower the height of your lights. I’m running my 6 bulb 4” above the water line. How high do you have them and what bulbs are you using?

I'm running 2 coral + and 2 blue + ramping up and down but 100% 9hrs a day. The LED cluster run a little longer but slower ramping and only to 70%.

They are about 9 inches from the water level.

 

[jda]

Browning is an issue with higher building blocks causing an excess of zoox in the coral... basically higher N and P can do this at different levels to different corals. They usually go green and then brown. Is this what is happening?

Paling is caused by too low of light and/or chemically stripping out all building blocks with media like GFO, Lan Chloride or organic carbon. Are the corals getting lighter in color? Sometimes these can look brownish, but it is a light brown with a tinge of the original color.

It is possible that 4x T5s is not cutting it. Do you have access to a good PAR meter, like an Apogee? If the corals are paling, then lower the light down a few inches and ramp it up to 11-12 hours of 100%. Ramping is for you and not the coral, so you can use the ramping time to get more light to the corals. If you cannot get the output to be higher, then more time will do the same thing (to a point) - the are some very conclusive studies on this.

Until you get fish again, I would consider tuning your skimmer so that it does not pull anything. I still like them for gas exchange, so just pull the collection cup or make it run so wet that it overflows back into the tank... something/anything like this.

 

[markalot]

I think he has 4t5s plus LED (ATI 4 x 80w Hybrid Powermodule lighting), and this could actually be too much light for a tank with very low nutrients. I don't have the ATI version but I do have a Nanobox created hybrid and I can get away with running just 2 T5's in the summer and still maintain good colors.

 

[Graffiti Spot]

Can you take closer pics of the corals?

 

[Graffiti Spot]

And how long have they been in the tank/where were they from?

 

[DesertReefT4r]

Just know you are not alone the fight against browing sps.

 

[Punchanello]

Thanks for all the great comments so far. I'm wondering if some of you were right about this being a case of paling and not browning. Maybe I'm just seeing more brown polyp and less colour.

The acro at the back in the photo (wild colony) used to pink towards the tips and green lower down. The Milli on the left had a green base and brilliant hot pink highlights. The one on the inner right was burnt orange with flouro orange highlights. The blob in the from was brown when I got it but used to have deep blue or purple 'tips'.

All have been in the tank at least 2-4 months and have based out and are growing.

I've turned off my skimmer off for now and reduced the photoperiod on the fuge light. Would adding aminos help?

 

[brett.sizeland]

Thanks for all the great comments so far. I'm wondering if some of you were right about this being a case of paling and not browning. Maybe I'm just seeing more brown polyp and less colour.

The acro at the back in the photo (wild colony) used to pink towards the tips and green lower down. The Milli on the left had a green base and brilliant hot pink highlights. The one on the inner right was burnt orange with flouro orange highlights. The blob in the from was brown when I got it but used to have deep blue or purple 'tips'.

All have been in the tank at least 2-4 months and have based out and are growing.

I've turned off my skimmer off for now and reduced the photoperiod on the fuge light. Would adding aminos help?

Yeah definitely looks like it's paling and not browning. Need to increase the nutrients or even if your not getting a reading if you are adding more food it will help.

I would probably leave the skimmer running as it's really good for adding oxygen to the tank just adjust it so it doesn't skim or not much at all.

Are you adding any Aminos at the moment? They will definitely help if you aren't adding any at the moment

 

[Newtybar]

I would add some fish.

 

[Punchanello]

Yeah definitely looks like it's paling and not browning. Need to increase the nutrients or even if your not getting a reading if you are adding more food it will help.

I would probably leave the skimmer running as it's really good for adding oxygen to the tank just adjust it so it doesn't skim or not much at all.

Are you adding any Aminos at the moment? They will definitely help if you aren't adding any at the moment

No not yet

 

[29bonsaireef]

Definitely paling, this is not the worst problem to have. As long as you're not doing any un-natural exporting, the corals will be okay, and should keep growing. As you get fish and feed more things will regain deeper colors. I would just keep doing what you're doing, throw some food in there everynow in then, even if you don't have fish. JFYI, some amino products and coral foods can start some weird algae/bacteria with low nutrients, so be carful on the amounts if you go that route

 

[jda]

Aminos will not really feed the coral directly since single cell organisms use them more efficiently, but they do get turned into N and P on the backend. Dosing pure nh4 might be the way to go... in small, frequent doses. However...

If you can read some color on Salifert, then you are totally fine. Even if you cannot, then you could be fine. I cannot every read any color on the nitrate test kit and I have more than enough with everything thriving. You really need a Hannah Ultra Low Phosphorous to tell if you are too low on P.

Again, most paling issues are with lighting.

 

[Punchanello]

Ok, feeling pretty stupid right now. Checked the settings on the power module and t5s were only running at full power for 6 hrs a day [emoji31][emoji849].

Currently bringing them up to 11hrs a day plus ramp up and down.

Have no idea when I messed that up.