LPS issues after switching to RODI

[DrDNA]

First off, my tank is a mixture of clams, SPS, and LPS. I have been running it for several months on my well water. The LPS and clams seemed to be doing fine but the SPS weren't very colorful and weren't really growing. I finally installed a RODI system about a month and half ago for water changes and top-off. Now, after having replaced about 50% of my old tank water with RODI-prepared water, some of my LPS are on their way out. These include a hammer coral and a couple elegans corals, although my branching frogspawn and goniopora are still expanding and not receding. The SPS, though, have colored up a lot and have good PE and are actually adding new growth, and the clams are still growing and adding new shell, as they always have been.
So, I guess my question is, why am I losing LPS corals? Is the new water "too clean" for them, are they actually better off with a high TDS water?

Anyway here are some tank params:
pH - 7.7 to 8.0
temp - 80-81
KH - 9.0dKH
Ca - 450ppm
PO4 - slightly measureable on the Salifert kit, but I am running phosphate sponge to bring it back to zero
NO3 - 5-10ppm
ORP - 425-450mV

lights are 4x250w DE 14K halides, circulation is 2x6100 tunze streams

Also one more note is that back in the summer I started feedign PE Mysis. Even with rinsing it before adding it to the tank, it did bring the water quality down, as indicated by the start of some cyano and measurable phosphate. I was adding about a 1" square of it into a 300g tank once a day.

Anyone have any ideas? To me it seems odd that the "more difficult" species like SPS and clams are doing okay while the LPS are having a tough time....

 

[Nu2SW]

I thought PE was suppose to be high quality and not have many phosphates???

 

[Underwaterparadise]

<a href=showthread.php?s=&postid=11060038#post11060038 target=_blank>Originally posted</a> by Nu2SW
I thought PE was suppose to be high quality and not have many phosphates???

I would attribute his water Quality issue to decaying shrimp that were not eaten rather then the product. The shrimp may naturally contain phosphate but they do not use any packing juice like the other brands. Thus PE mysis has 0% moisture VS.other brands that are 90% moisture aka Phosphate juice


What is your MG. reading? Such an overlooked thing today. Yours should be fine if your CA. is 450 but I would still check it. Also check Strotium levels. Both of those are vital to most LPS corals. Have you intorduced anything new to the tank? Your PH seems a lil low but some people run it low.

 

[DrDNA]

I'll check my Mg this weekend. I don't have a Sr test kit, may go see if John has any over at YR. The pH runs low because of two reasons, at least IMO: 1) DSB and 2) I run a calcium reactor. However, I did just finish hooking up my auto top-off and will use kalk for all my top-off water. I don't really have the space for a refugium, unfortunately.

I haven't introduced anything new in quite a while, like a couple months, except for an ORA German green frag and a piece of red plating Monti, both from YR.

 

[Fragmented]

Can you describe "on their way out"?

It may help to target feed them. If the water is so much cleaner than they are used to, they may need more nutrients to do well.

 

[MrMikeB]

Pictures would definitely help too. Also, how long did it take to be at 50% saturation with the new water with water changes and top off?

 

[DrDNA]

Hey all,

Sorry for not posting back to my own thread sooner...
Basically what happened to my hammer and two elegance corals was that they essentially RTN'd. Lost one elegance coral altogether and the other elegance and hammer coral are about 50% gone.

My system volume is around 250gal, when you figure in live rock, DSB, and then add the sump volume. Regarding the timeline, I got my RODI system online the first week of this month. Since that time (so about three weeks elapsed time), I have done 3 50gal water changes using RODI water, for 150gal total. I am planning to do another 50gal next weekend. It is during this time that those specific LPS corals have had their problems. Again, though, I have a branching frogspawn that is doing fine (no tissue recession and full polyp extension), and the SPS actually are looking more colorful and have better PE than before.

Previously, in late summer / early Sept, some of my SPS began to bleach and the LPS didn't expand much. A series of water tests indicated the presence and accumulation of copper in my system, as I had been using my well water for top-off (I know, not the smartest move in retrospect). I then ran Cuprisorb in a Phosban reactor (in its own mesh bag of course) which brought the copper back to undetectable levels.


So, my poor corals have certainly been through their share of mishaps....

 

[TeeLapia]

Since you found some bad elements... The rocks in your system are like sponges. May I point out that though you may not read copper levels any longer. Your rocks have sucked up the copper and can be releasing it in undetectable amounts. I do not remember where I read this (Somewhere in the reefkeeping issues). Just something to think about, I know it's something you didn't want to hear, but I thought something you need to know.
That is why you should never have liverock in your QT tank as well

 

[Fragmented]

How long has this system been set up?

How long have the LPS in question been in the system?

Is it possible that they have been in decline and this change just accelerated it?

One major key to reefkeeping is doing things gradually and with patience.

 

[plankton]

Jeff - some things to try.

1) Measure your nitrite and ammonia

2) Your pH is a bit low even with a ca rx. Try backing off on your effluent from the CaRx and/or add a fan to where the effluent drips in and see if the added air raises the pH at all. Also, if you have not recalibrated your pH probe recently try that and see if you still get the same pH.

3) You say you exchanged roughly 50% of your water but didn't say over what period of time. This would be potentially very important because some corals are very, very sensitive to changes in Alk. e.g. Purple Monster, deep water species, etc.

Scott

 

[DrDNA]

Here is some additional background on my system. It has been running now for about 10 months. The corals in question have been with me about six months. I also have some maxima clams that have been with me just as long that are expanding as much as they always have.

Fragmented-
So, I've had the LPS in question for several months each. They hadn't been expanding as much us usual before I switched to RODI, which is what tipped me off to check the parameters I don't typically test (i.e. copper). They were already stressed before I started doing the water changes with RODI water, so I suppose that the "better" water chemistry change sent them over the edge.

IIRC, I did a 50 gal water change a few days after I got my RODI system running. I did another one about 4 days later, and a third about a week after that. That was now about two weeks ago.

Scott-
I haven't tested the ammonia and nitrites and I would be shocked if they tested more than zero, mainly because my problems are limited to a few individuals, not the acros, clams, and fish. But, I will check them anyway.

Regarding the CaRx, I run it with a steady stream for an effluent and have its pH controller set for 7.0. John at YR had recommended to me to run the reactor at pH 7 when using ARM media, but to run it lower for other brands. I have to run it at a faster flow rate to keep up with alk demand in my tank. Alternative, I can try slowing down the effluent rate and also dropping the pH of the reactor to make the ARM media dissolve faster. Also, I have the effluent empty into a small container in the sump which has an airstone to drive off some excess CO2. Anyway, I have always had a problem keeping my pH up, again which I think is due to both a CaRx and 5" DSB.

Thanks again all of you for your ideas and suggestions!

 

[DrDNA]

Underwaterparadise
Okay I checked my Mg this evening, it was around 1275ppm.

 

[plankton]

Jeff - You haven't by chance recently disturbed your 5" DSB have you? As, here are things at the bottom of your 5" sand bed you want to stay at that layer and not surface! One friend removed part of his established sand bed only to loose many fish, several corals and cause a large algae bloom. Exactly why these things occured I'll leave to others to discuss, but one possibility...
Scott

 

[Underwaterparadise]

<a href=showthread.php?s=&postid=11079040#post11079040 target=_blank>Originally posted</a> by DrDNA
Underwaterparadise
Okay I checked my Mg this evening, it was around 1275ppm.

I'm surprised your CA. is that high with the MG. being below 1280. I try to run my MG at 1300-1350. Also did you have any big swings in the salinty when you did the WG? I have seen perfectly healthy LPS die overnight from a .2 swing in the salinity.

 

[DrDNA]

I haven't disturbed the sandbed, no digging around in it or removing any of it.

As for the Mg - Ca question, I do add Seachem's "reef advantage calcium", which is a calcium chloride based calcium additive. Supposedly it also contains Sr and Mg. The main reason I have to dose calcium is because my CaRx doesn't keep up with calcium demand, although it does keep the KH around 9-10 dKH. Otherwise, my calcium will eventually fall off to around 375ppm.
However, now that I have set up my auto-topoff using kalk, it may change the calcium equation some. So, do you think I should add Mg to my system? I do have a container of seachem magnesium supplement I can use....

 

[Underwaterparadise]

Wouldn't hurt but I don't think that was the problem. What about sudden change in Salinity?

 

[DrDNA]

I keep my salinity between 1.025-026 using a refractometer. It is certainly possible that a salinity change was the culprit though, at least with the makeup water. IIRC, I think of the batches of replacement water I made was around 1.028 since I was trying to bring my tank from 1.025 up to 1.026. Lesson learned I suppose, but it still baffles me that I didn't kill my SPS at the same time...