Coral coluration loss
 

I did a post a while back when I bough a piece of Green Acro and wtihin two week it had turned brown and still is was told if was a nutrient level too high, Nitrates and Phosphates are testing zero but I have a small brown algae on the back glass and a little bit of loose hair algae on one end easily pulls off the glass,

Dosing Ca, Alk and Mg daily occaisional iron and Iodine and Potassium.

have been reading in various forums that raising Nitrates to levels 1 to 5 with Potassium Nitrate helps with reducing coral browning and restoring natural colours has anybody else tried this with any success

"browning" can be from not enough light...

The population of zooxanthellae cells has increased in a effort to increase nutrients to the corals.. Those cells are usually a brownish color

Coral coloration is a very complicated issue. What kind of lighting are you using? Bulbs (not LED) fade over time, which can be an issue. I haven't heard that adding nutrients will reduce brown coloration, although it seems to help with colors that have faded.

Another thought would be to try a bit of GFO. If there is much phosphate flow in the system, the GFO might be able to outcompete the zooxanthellae in the coral, and reduce the browning, if Zooxanthellae growth is the issue.

Lights are Dsuny 2 x 40 led's running about 70% starting blue at 7am and ramping up 4 channels by 11 and back to blue at 1am (last look before bed) corals are growing well plating montipora and branching all have white edges and tips, most corals look ok but have lost colour have a moon brain was grey with blue centres now totally grey, at the moment these threads sound promising so willing to try if raising nitrates will help increase colour only £5 so not expensive if no good.

If they are losing color, the nitrate might help. It is cheap to try.

I agree with nitrates. In my experience it can take 1-2 months to get full color changes. So, don't change too many things at once and give them time before trying something else.

First off what are you levels at for cal, alk, mg, ph and eanything else you are dosing. If you are not testing for dont dose it. Minor trace elements ime really dont need to be does and are replenished with water changes using a quality salt mix. Cal, alk, mag, P and K are all you should be concerned with. Having low but detectable levels of No3 and Po4 are important to coral color and health. Proper lighting plays a key role as well as does strong random flow. Get good test kits like Salifert, Hanna, Elos ect keep the important elements at nsw ranges, keep No3 around 3-.8ppm and Po4 1-.05 ppm I have found keeps a nice balance and colors will improve. Lots of well fed fish, strong lighting and flow and a good skimmer are important.

Browing can occur from too much and/or too little light or high nutrients and other stress factors such as moving the corals around too much or acclimation.

Are you using your nitrate test the right way? I also thought I had 0 nitrates but I kept seeing algae issues and my anemone was browning. When I finally followed the instructions to a t I actually had 160ppm nitrate.

Wow 0 to 160 ppm is a big difference. Agree though make sure test are performed correctly.

Started dosing 100ml daily Potassium Nitrate solution 1/4 tsp in 400ml on Monda,y tested yesterday and had a positive reading of 2ppm.

Tested Today Ca 455, Alk 9.9, Mg1350, Potassium yesterday 370 dosed 8gm to raise 10ppm

Normally add 5ml Iron weekly and 2 drops Iodine and Potassium Chloride every 8 days.

Lighting is Dsuny 2 x 40 about 80% and Gyre 230 on 50% max (Elegance coral on bottom gets a lot of flow on the return leg)

Last water change 2 months ago, all corals growing well

Make sure you have enough phosphate if you're dosing nitrate.
http://www.sciencedirect.com/science...601?via%3Dihub
https://www.nature.com/articles/nclimate1661

As mentioned above coloration in corals is a very complex subject and we really need to treat each species and genotype individually. We also need to be tracking the history of corals as they have "memories" of the conditions they grew in which will be a factor to adapting to new conditions.
https://www.academia.edu/11590694/De...n_a_reef_coral
Sadly, we also still have a very poor understanding of the role melanin (an essential pigment that is part of corals immune response) plays in coloring corals that are having bacterial issues.

Watch the potassium nitrate dosing. As you increase potassium your nitrates also increase might be part the the reason you have 160 ppm no3. Imo 2 months with no water changes is not good for a reef tank and is the main reason your trace elements are so low. Small weelky water changes replenish trace elements and export waste. Your alk is a little high I shoot for about 8 dkh. Sorry but dont know what a Dsuny light is so I have no idea there. LED? Watts? Type of LEDs and what specturm combo?

DesertReefT4R think you are getting your messages crossed my N03 is 2ppm not 160 that's JustAClownFish's comments. I find no water changes has little effect on my coral growth, there may be some trace elements not being replenished. The 2 x 40 LED Dsuny lights I have are from Ebay Chineses made 4 channel WiFi I find they give excellent light over my 44 inch for £200

I agree with TimFish about the phosphates. As the corals and other inhabitants absorb the nitrate they will absorb phosphates as well. If there is no phosphate then they wont be able to absorb the nitrate. There is a relationship between the two. The best example I could think of would be the relationship between Alk and Ca. Others have recommended Sodium Triphosphate. Just saying you might want to dose both. Make sure there is a least a measurable amount of phosphate.

just looking at your photos i would say you have a nutrient issue as in to much no3/po4 and possibly a flow issue as i can only see a little power head at the bottom, are you running an over flow box? is it a marisys? a photo of your sump would be appreciated.... what sort of skimmer are you using?

Spslvr Thepowerhead you mention was to blow away some brown aglae I have in the RedSea 130 only, this tank has an overflow into a common sump ,(no brown algae in the 44 inch dt

With my old Red Sea test kit (£50 now exhausted ( I was getting 0.5 Nitrates and between 0.04 - 0.08 phosphates, now using a Salifert which shows both as virtually undeectable,

Been dosing with Potassium Nitrate for about a week now and Nitrates are visible on the Salifert at 2ppm will raise slowly ove ra month to see if corals respond to a colour change

Update, Been dosing KN03 since Sunday 2 tsp in 1.75 litres RODI, dosing 10x20ml daily Nitrates have risen yesterday and today to 2.5ppm. Two of my Pocillopora in my larger 44" have signs of bleaching whereas the Pocilopora in my Red Sea 130 (tanks are joined) is fine, lighting is more intense in the 44" dont know if this has any bearing on the bleaching, all other SPS in the 44" are fine so intend to continue with the dosing , how long should I dose at 2.5ppm before raising slowly to 10ppm, have read it may take a month or so to see and colour change

All of the algae in that pic makes me doubt low nutrients are your issue. Looks like high nutrients are your issue. My SPS have only browned from dipping, stress from moving or high nutrients. Low causes them to be pale not brown.

+1

I think you're just going to feed the algae

I would keep the nitrate level where it is or consider letting it drop. 10 ppm is higher than should be needed by any stony coral in the trade. I agree that the coral browning problem might be caused by nitrate and phosphate in the water column. Coral coloration is a complicated issue. I'd be cautious with any changes. If the corals continue to do reasonably well, then keeping the nitrate level at 2.5 ppm for a few weeks might be a good experiment. I am concerned about the bleaching, though, and might back off on the nitrate dosing.