Tips starting to show stress @ 7.5 alkalinity...?

[Potatohead]

I find this very interesting. My tank is mostly acropora and I typically run my tank in the 6.9 - 7.2 range and have for several years. Occasionally it will go up to about 7.4 after water changes but usually comes back down within a day or so. I did a water change on Saturday and it went up to 7.5. I guess because winter now and the house is all closed up it stayed at 7.5 for a few days. On Monday I noticed a lot more mesenterial filaments and a little bit of pale color in one or two corals. Most others look normal. Then last night I noticed one or two have the very beginning stages of tip burning, I tested my alk and it is still at 7.4. I reduced my alk dose about 30% and will likely be back to 7.2 or so by tonight.

Has anyone seen this kind of thing with alk this low before? I mean it could be something else of course but I think that would be somewhat coincidental, I haven't changed salts or anything like that in a long time. I have no idea why but this is not the first time this has happened either, and for some reason my tank highly prefers quite low alkalinity.

I know some people will ask, my nitrate is about 8-10 and my phosphate about .12


Edit - Maybe I should have posted this in the SPS forum...

 

[TDEcoral]

Acros are like women, trying to find an explanation for everything they do will drive you crazy.

 

[stephj03]

Maybe raise nutrients a bit? Extra feedings?

 

[Potatohead]

I guess the only other thing I can think was I refilled back into a different spot in the display. My water change water alk is about 8.5. So I guess it is possible some corals were exposed to a decent momentary swing. I do normally refill into the display but more on the side and this was more in the middle. I don't know if that would be enough to do it.

 

[watchguy123]

I find it very difficult to problem solve somebody else's tank, but I will share a penny and a half of suggestions. SPS tip burning and increasing alkalinity immediately leads me to guess that your nitrates are generally low. General rule, if nitrates are in a relatively low level, alkalinity needs to be at a low level as well. But your nitrates are reported at 8-10 ppm. In my mind, 8-10 ppm is a pretty forgiving nitrate level. So my next best guess is that maybe your nitrate or alkalinity test is off or more likely I am just wrong. I generally keep my nitrates in a range of 2-10 ppm (that is about as good as I can read the pinks on the salifert test) and my alkalinity around 7.5 dKh with swings of about 0.5 dKh over time. Regardless, I find my tank pretty accommodating to fluctuations in both alkalinity and nitrates. I have run out of CO2 in my cylinder previously, and have had alkalinity drop fairly precipitously without noticeable effect. I think your thoughts are on target, just lower your alkalinity to its typical and usual level.

 

[Reefahholic]

I find this very interesting. My tank is mostly acropora and I typically run my tank in the 6.9 - 7.2 range and have for several years. Occasionally it will go up to about 7.4 after water changes but usually comes back down within a day or so. I did a water change on Saturday and it went up to 7.5. I guess because winter now and the house is all closed up it stayed at 7.5 for a few days. On Monday I noticed a lot more mesenterial filaments and a little bit of pale color in one or two corals. Most others look normal. Then last night I noticed one or two have the very beginning stages of tip burning, I tested my alk and it is still at 7.4. I reduced my alk dose about 30% and will likely be back to 7.2 or so by tonight.

Has anyone seen this kind of thing with alk this low before? I mean it could be something else of course but I think that would be somewhat coincidental, I haven't changed salts or anything like that in a long time. I have no idea why but this is not the first time this has happened either, and for some reason my tank highly prefers quite low alkalinity.

I know some people will ask, my nitrate is about 8-10 and my phosphate about .12


Edit - Maybe I should have posted this in the SPS forum...

I’ve had this happen from a trace element overdose. So maybe double check that.

Have also had some start to STN a little down from the tips because of phosphate dipping to low. They were in 400+ PAR and were limited on resources. You can literally see how I caught it and recovered it.

 

[Charlie’s Frags]

I guess the only other thing I can think was I refilled back into a different spot in the display. My water change water alk is about 8.5. So I guess it is possible some corals were exposed to a decent momentary swing. I do normally refill into the display but more on the side and this was more in the middle. I don't know if that would be enough to do it.

I like your no3/po4 levels but are you carbon dosing or using gfo?

Another possible culprit would be if your corals were exposed to air during your water change and the lights were full blast.

 

[Ashish Patel]

.3 dkh is hardly enough to cause any issue with acros. Maybe look at other changes over the past few weeks. I've had mine dip 2DKH in few days and a few acros perished but most recovered as I just bought it back to the 7 - 7.5 dkh I prefer. I do let it go up to 8dkh over the course of few months but if its gradual changes then they can acclimate.

 

[SamMule]

Could it be a PH swing?

 

[Potatohead]

Anything is possible with the test kits. However they are not old and seem fairly consistent. Red Sea Nitrate Pro and Hanna checker for alk and phos which for me is always pretty darned reliable. The phosphate checker is a new one after my old one packed it in a few months ago. I do have a reagent standard and it was measuring about 20% high compared to the old one but the reagent standard also says to only use it once so I am not sure if that was correct. In any event my phos is testing around .13 and if that's 20% too high it is still about .1 which is fine. I do not use carbon (dosing) or GFO.

I should also clarify that 'burnt tips' aren't really burnt tips. Just not great looking tissue and some mesenterial filaments. There is no actual skeleton other than growth tips.

These are the changes I have made in the last couple months:

- Removed my filter roller, which has cause my nitrate to climb from about 2 to 8-10
- Because nutrients are higher I stopped dosing any aminos and 'color' trace elements. However the dose I was using was VERY small (like 1/8 the recommendation)
- Again because nutrients are higher I am feeding slightly less but still ~3 times a day
- Increased fuge lighting from seven hours to eight approx a month ago and then again to nine hours about ten days ago.

The pH comment is interesting. This time of year now obviously the house is closed up. I don't have a pH monitor but it is almost a certainty it is lower than a few months ago. I have been considering adding a CO2 scrubber for months but the below applies...

None of this seems like any kind of major shift, so I am not really sure. Unless things start to really go sideways I am not going to make any more changes for a while.

 

[Potatohead]

So I posted in the other phopshates thread I have going on that I noticed last night my glass is staying a lot cleaner than normal. My last three tests over four days with the phosphorous ULR were 41, 42 and 44. I don't believe this is wrong because it has been consistent for a while. I tested nitrate last night and again it is 8-10 range.

So I am concluding that it is likely my organics are lower than normal. I know that sounds counter-intuitive to removing the filter roller but I did stop using aminos and what not and my skimmer is absolutely pulling more gunk out without the roller. It seems to jive with what I am seeing with the the cleaner glass and the reaction of some of my corals. I am going to up my feeding a bit more, maybe go back to a very small amino dose and make no other changes and see how that goes.

 

[jda]

I don't believe that alk swings bother healthy coral much unless it is consistently inconsistent day after day - I have had a few times where my co2 tank ran empty (hangs head in shame) and I went from 7.0 to 4.0 back to 7.0 all in the same day. I don't let this happen all the time, though.

Probably something with the water change. Do you use a bucket that was not dry mixed? I don't care what anybody says, salt that sits and especially travels a long way (like Tropic Marin from Germany) can have inconsistent batches in the same bucket if not mixed up. If you use a whole bag at once, like IO or RC, then this is not an issue.

Like others have said, you might never know what happened.

 

[Potatohead]

It was a newer bucket but I have used it three or four times. I do dry mix them, and I did test the alk on the first batch as well. Typically all I test from that point on is salinity at each water change.

You are probably right about not knowing, which is fine as long as everything recovers ok

 

[Viking_Reefing]

Just out of curiosity, if you are generally running your alk around 7, why are you using a salt mix with a much higher alk?

 

[Potatohead]

Just out of curiosity, if you are generally running your alk around 7, why are you using a salt mix with a much higher alk?

If I had more options here I would use something lower. I live in Vancouver, shipping salt in Canada is not really an option and nobody carries Tropic Marin or Brightwell locally. I use Red Sea blue which is supposed to be about 8 but IME is more like 8.3-8.4 typically. I do have the ability to lower the alk in the mixing container and sometimes I do but Red Sea also says not to mix the salt for more than four hours. So I don't know.

 

[Greg P]

Us unfortunate folks here in BC have limited options for salt. They are either ideal at a much higher price than you brothers and sister in the States pay, or we deal with less than ideal parameters at an affordable cost.
A bucket of IO is $53
A bucket of RS Blue is $87
Both are prices without taxes and shipping.
We have other options, but you get the idea
We deal with what we can/want to afford

 

[Greg P]

FWIW, I've mixed RS Blue overnight with a powerhead and heater. No changes in params from a couple hours to 24 hours

 

[Greg P]

Have you considered using IO and Muriatic Acid to lower the Alk to your desired level?

 

[Potatohead]

I have done that in the past with other brands yes. I've just never had a problem until now with RS out of the box.

After a few days I am not convinced it has to do with the water change it was just my initial thought. I am pretty sure it has to do with removing my filter roller about six weeks ago. My nutrients still test fine but my glass is staying much cleaner. I also changed carbon last water change as well for the first time in a couple months which if it is a low organic carbon problem could have made it worse.

 

[Greg P]

I stopped running both carbon and gfo back in early 2016.
My corals grew fast enough that sumer 2019 I had to start dosing nitrogen and phosphorus to keep my levels 0.03-0.06 and 2-5ppm.
At that point my glass also was staying cleaner than normal - as you mentioned.
I kept my params similar to yours, with the exception of lowering Alk to 7.5-7.7 to stay within the lower nutrients range.

I'm sure you've already done it but, have a serious look back through your records over the last couple months for anything you've changed.
The one thing that sticks out to me is your carbon change. Is it the same container you used last time? Did you rinse it well as you always do? Is it being beat to poop in your reactor this time and being turned to dust?

Good luck !