Several Corals not well, others okay. Ideas?

[Richard Newman]

Hi folks.
Several weeks ago I had a large spike in po3. It was 1.62. I deep cleaned the AIO filtration area, replace the carbon / GFO, cleaned the skimmer, cleaned the pump, etc. Two large water changes that week, and 50% every other week. Nitrates and Phosphates have been stable the last 3 weeks. NO3 at 15 and PO3 at .1 (yeah, still a little high, but that is what my tank has run since it was setup 2 years ago).

Current set of parms are:
Temp: 76.4 F
Salinity: 34.9 PSU
PH: 7.9
Alk: 9.2
NO3: 14
PO3: .12
Calc: 450
Mag: 1500

Three weeks ago the alk was down to 7.6, but water changes and (fixed) dosing has brought it back up.

My hammer, torch, duncan, and acans are all not well. Very little growth and the torch, duncan and hammer have been receding/shrinking. Pics are below.

Ideas?

Thanks!

 

[Dkmoo]

Just looking at param, a few points

1) ph is low. I know guidance say 7.7 to 8.3, but there is huge diff in carbonate concentration between the two extremes. Corals can tolerate this range, but will have much harder time calcifying in lower pH. It also looks like you have not a lot of coraline. Another sign of low pH despite good alk and CA levels.

2) po4 is high. Try to get it down more.

3) I know you said these have been this way for a couple of years but just because corals don't die right away or show that they are struggling all these times, doesn't mean that it was a good environment that they can healthily grow. Low ph especially impacts stony corals. There are successful low pH reefs but their other params and feeding may make up for it by being better. In your tank they are likely weak or sensitive to minor environmental stressors from long term effects of this environment, so whatever you did last few weeks caused enough change that tipped the scale, resulting in what you see now.

I'd try to get pH to 8.2. You will see much better coraline growth and the lps should improve.

Just do it slowly.

Your Alk level should have supported pH in the 8.3 range. 7.9 likely due to high co2 concentration. Consider a co2 scrubber. Or if yiu currently dose sodium bicarbonate for alk (ie, red sea foundation b), then switch to soda ash will raise pH. This can be DIYed, or buy the BRS soda ash mix.

 

[PghReef]

I wouldn't chase ph too much, chafing numbers causes more problems then it solve usually. Stability is key and buffers don't provide any stability, just quick spikes and dips. Not to mention how accurate is our ph test kit? Many people run around 7.8 or 8 successfully, but 8.2 is more ideal.

If your ph truly is a problem then fresh air or a cold scrubber would be you best options.


As for the problem, to me your tank scans you mention alk and phos spikes and dips. has to go slow or bad things happen. Also any new additions? I find that lps that have issues with unexplained deterioration is often a cascading effect that spreads from one head to another throughout the colony and from one colony to another until they all look terrible. I personally believe it's done sorry of bacterial infection, and antibiotics such as cipro like used one anemones or fw dips seems to be the best option. Pick up the coral, does it smel llike rotting flesh? Are the mouths gaping? If so it's already a goner.

 

[PghReef]

Also, thank you for providing specs. I forgot to mention 50% WC. To me that right there also leads to a lot of instability and swings. I do 5gal on my roughly 115gallon system weekly. That's 4-5% at a time. About 20% a month total. I don't cause any swings in my parameters.
Also do you have an ato?
Do you have good coralline growth?
How did you start? Dry or live rock?

 

[Dkmoo]

Its never good to chase numbers blindly but the effect of pH on long term stony coral growth and health is well documented. Chasing numbers "with eyes wide open " IMO is well worth it to improve the health if the tank

Look up ocean acidification and its impact on reefs. That is a drop in pH from 8.25 to 8.14.

At pH of 7.8, stony corals will have a very hard time making bones due to the low concentration of carbonates. Corals can pull bicarbonate to bind with calcium but will have to spend energy to pump the extra H ion out. This means their tissue likely has even lower pH that the surrounding water.

below 7.7, caco3 starts to disolve.

7.6 is the pH of many carx where melting old coral bones is the designed chemical reaction

Dosing soda ash works if you have an autodoser that can break it up to multiple times a day, if you are dosing weekly then won't help you. High co2 is the source of the low pH, so scrubbers and better outside air exchange is the long term solution. Point of alk level is to maintain stable pH and help fuel CACO3 formation. But if the stable pH reached is an environment that is inhibiting caco3 formation then you are not getting the most benefit out of the tank.

 

[PghReef]

Its never good to chase numbers blindly but the effect of pH on long term stony coral growth and health is well documented. Chasing numbers "with eyes wide open " IMO is well worth it to improve the health if the tank

Look up ocean acidification and its impact on reefs. That is a drop in pH from 8.25 to 8.14.

At pH of 7.8, stony corals will have a very hard time making bones due to the low concentration of carbonates. Corals can pull bicarbonate to bind with calcium but will have to spend energy to pump the extra H ion out. This means their tissue likely has even lower pH that the surrounding water.

below 7.7, caco3 starts to disolve.

7.6 is the pH of many carx where melting old coral bones is the designed chemical reaction

Dosing soda ash works if you have an autodoser that can break it up to multiple times a day, if you are dosing weekly then won't help you. High co2 is the source of the low pH, so scrubbers and better outside air exchange is the long term solution. Point of alk level is to maintain stable pH and help fuel CACO3 formation. But if the stable pH reached is an environment that is inhibiting caco3 formation then you are not getting the most benefit out of the tank.

Agreed, but if he's had corals growing for 2 years then either they've adapted to his ph or the measurement is inaccurate. We often really on color test kits that have a lot of room for error where .1 or .2 makes a huge difference in coral heath, but not a difference in color or or perception of the color. Also using digital read it's is better IMO but still not fool proof. They need calibrated frequently, and have a margin of error themselves.

I agree fresh air is the best long term solution. If that's not doable then a co2 scrubber will work, just more maintenance and cost. If the ph hadnt changed recently but the corals took a sudden downturn, then I'd be looking for other culprits. Whether it be recent alk or phos swings , new fish additions causing nipping( don't think that's his issue), recent coral additions that could have brought a new pest or disease, a new salt or batch of salt, or some other recent change.

 

[moz71]

My lonely opinion is the I stability you mention,. The ups and downs of the po3 and alk. I have noticed it is a delayed long term issue on corals. Meaning you don’t necessarily see the issues the days it happens but weeks later. I would just get it stable and hope for best. Your levels at now are fine. Let it be for awhile let them stabilize.

 

[Dkmoo]

Agreed, but if he's had corals growing for 2 years then either they've adapted to his ph or the measurement is inaccurate. We often really on color test kits that have a lot of room for error where .1 or .2 makes a huge difference in coral heath, but not a difference in color or or perception of the color. Also using digital read it's is better IMO but still not fool proof. They need calibrated frequently, and have a margin of error themselves.

I agree fresh air is the best long term solution. If that's not doable then a co2 scrubber will work, just more maintenance and cost. If the ph hadnt changed recently but the corals took a sudden downturn, then I'd be looking for other culprits. Whether it be recent alk or phos swings , new fish additions causing nipping( don't think that's his issue), recent coral additions that could have brought a new pest or disease, a new salt or batch of salt, or some other recent change.

Yup agree there is a lot of noise in hobby grade pH readings so a lot of time I agree that if reef is looking good on 7.9, maybe its ok.

Assuming the reading is accurate, low pH has a few long term affects on stony corals even if they has adapted to the environment over 2 years - ie, low bone density, and weak immune system (due to extra energy spent pumping the +H ion from the low pH tissues)

My tank is the perfect example of this - it had been running at 7.8 for 3 years and my torch had adapted - bought it when it was 1 branch 6 heads. In the 3 years, it grew to 30 heads, I sold 15 for store credit, and the remaining 15 grew to 25 heads by the end of year 3 and looks good. By all measurements it was successful and thriving, yet, the bones are so brittle that any accidentally tap would break off a few branches. My initial colony became 5 separate colonies due to this accidental fragging. And whenever there was some stability change - heater broken, too large WC, algae bloom, I would lose a few heads. The OPs issue sounds like what i went thru when LPS just "die" from seemingly little stress. To me this does not mean I have a healthy colony despite the growth and outward appearance.

During this time I also had little coraline algae. Looking at OPs tank shots it looks like he has no coraline either, which is why I suggest pH as the underlying issue here.

4 months ago I finally understood the importance of pH and increased it to 8.3 using all the methods that I suggested initially. In 4 month, coraline has completely taken over the rockwork and tank. The 25 torch heads became 35, all my other corals that had struggled in my old tank all are improving. New frag survival rates became 100%, now I purposely buy struggling corals for discount and rescue corals for free from local reef community hobbyists. Everything has looked noticeablly better and pH is the only big thing I changed.

 

[Richard Newman]

Hi all, many, many thanks for all the replies!
It has def been in interesting journey the last two years.
I did spend a very long amount of time reading (lots from this site thanks!) before even getting the tank. The two biggest take aways are patience and stability. The values provided for standard sea water, are just those, an average from a very large vast space of the global oceans. Each micro environment owner decides what their values are going to be and then set routines or automation to achieve those goals.

To try and answer some of the questions asked. There is coraline algae throughout the tank. However, as a few mentioned it isn't as prevalent as it probably should be for a 2 year old tank. Interesting thoughts on the pH levels for this. Currently I dose All-for-reef (diy mix, minus mag since I don't need it added) and Nopox. This is done on a doser. There was an issue with the AFR dosing head (leak) which caused the drop in Alk. It's been replaced, and Alk has been probably over compensated for. I haven't really considered a Co2 scrubber as that is yet another piece of equipment needing maintenance. We do have rather good airflow in our house. I do have an air pump. I'll pick up an airstone when I get RODI today. Possibly with the airstone and skimmer the gas exchange will be better. It's quick and easy. I'll post updates later this week as to the results. The other pH solution is a diy dosing method with one of my free heads. Again a rather simple solution.

As for changes in the tank. The last fish (corris wrase) was added probably 6 months ago. And the most recent death was Christmas Eve of our Firefish. As I mentioned the nutrients spiked, notably the phosphate to over 1.6. This is what started the biweekly large water changes. Doing that has had a significant impact on getting No3 and Po3 under control. No3 is now under 15 and Po3 is hovering around .12. Still higher than the average, but back to where the tank normally sits.

The first indication there was a significant problem were the SPS corals. The monti's were bleaching and the bird's nests had no polyp extension. Right now the SPS are all back to normal save one, my green birds nest, I don't think it survived, but I keep watching. The other LPS and soft corals are now seemingly struggling, but not all of them. The candy canes are awesome, as are the GSP, pulsating xenias, and zoas. The acans are a mixed bag. One is doing really well, the other two not so good.

So, for now I'll try the quick easy suggestions first to raise the pH (slowly). I'll go back to the 5gal biweekly water changes as the nutrients are stable (I am also feeding less since I'm rather a heavy feeder...who isn't lol).

For anyone wanting to see the tank's progress, take a look at my build thread.

I'll post updates with my progress.

Thanks!