Questions for some reef guru's...

[Erik2302]

First off, I've had successful reef tanks in the past...I've just been out of the hobby a while and am having some difficulty keeping everything healthy.

Tank and Sump - 200+ gallons total volume
Lighting - 2 ecotech xr30w pro's about 13" over the water (no tops) running at 85%
Flow through sump is about 800 gph...
Flow in tank using an maxspect gyre 150, tuned down...
Skimmer is rated for a 300gal tank
Have chaeto growing in sump on opposite lighting schedule, started with a tennisball size lump like 3-4 weeks ago, its probably the size of a basketball now.
Bag of carbon in high flow part of sump.
170ish lbs live rock

Levels checked last thurs:
PH: 7.85 - 7.95 over the course of a day...but mostly on the low side.
ALK: 11-14 has been on the high side.
CALCIUM: 500
Nitrates: Undetectable
Phosphates less than .16
Magnesium: 1300
SG: 1.025 to 1.026
Temp 78-80

So on to the actual problem...I've lost 3ish relatively easy to keep corals over the last month or so.
One was a 10p colony of zoas, the other on its way out is a 3 head piece of frogspawn and the last that has been struggling along is a 3 head piece of hammer coral. Everything else appears healthy (I have SPS, zoas, other LPS all scattered around the tank nothing too close.

I'm concerned about the unexplainable coral deaths...and the relative lack of growth. Coraline algae growth has been very slow as well. Does this kinda just happen with certain corals? Or is there something I can do to fix this...The corals that died all appeared healthy at acclimation, i spot feed about 3-4 times a week.

I also would like to raise the PH without raising the alkalinity anymore than it already is...

[crabbysd]

Hey bud, for the ph you prob want to add air, its the easiest. Po is maybe a lil high but the no you might want more actually. Zoas like it dirty. Are you running gfo, phosguard and such?
And Fwiw Ive been having better success with more flow than less for most stuff.

[cmsurfr22]

what are the dimensions of the tank? and what skimmer do you have? also what fish do you have and how big are they? what kind of water/salt are you using?

[Erik2302]

72x24x25 I think...

Simplicity 320dc

I have two clowns a yellow watchman and a coral beauty.

Using rodi, 15tds in and 0tds out.

Using instant ocean reef...


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[calreef18]

I would let the alk come down to more normal range 7.5-8, if you're pretty low nutrient higher alk can cause problems sometimes. What were the symptoms for the Zoas frogs and hammer dying?
Tissue falling off? Brown jelly?

[Erik2302]

The Zoas just closed up one day and never reopened. Other Zoas nearby even of the same type were fine.

The hammer has some tissue falling off and I have noticed some brown jelly in the cracks of the skeleton. I've dipped it a few times and it's hanging on but not looking good. The frogspawn has no brown jelly...just never really opens fully and now some tissue has fallen off.


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[Kris]

Are you running a calcium reactor? (Low pH)

Are you feeding the corals? (Low nitrates)

Your TDS intake is damn near low enough to use to mix directly. (Mine in oceanside is 300-500 intake!) Do you have a home water filtration system, or is your TDS meter not working?

[cmsurfr22]

Yeah those tds readings don't seem right

[cmsurfr22]

also i've had a few things die in my tanks over the years, for no apparent reason, there any number of 1000 things that can cause that, so don't stress about it too much, it happens.

[Erik2302]

What's the best way to troubleshoot a tds meter? I thought it was low but after checking my areas water supply I didn't think it was out of the realm of possibility.

I've tested the rodi water and the fresh mixed sw both have unreadable phosphates and nitrates.


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[crabbysd]

also i've had a few things die in my tanks over the years, for no apparent reason, there any number of 1000 things that can cause that, so don't stress about it too much, it happens.

this +1

[cmsurfr22]

Best way to test the tds meter is with another tds meter

[Kris]

What's the best way to troubleshoot a tds meter? I thought it was low but after checking my areas water supply I didn't think it was out of the realm of possibility.

I've tested the rodi water and the fresh mixed sw both have unreadable phosphates and nitrates.


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Some people are adding nitrate and phosphate as it turns out coral seems to like to eat those in trace amounts.

If you can "taste" your water supply then it probably has more TDS than 15.

[Erik2302]

Yeah I messed with it a little...it's one of those HM units that comes with the BRS rodi systems, it's starts at 300+ then drops to about 20 as its running...and 1 on the output now.


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[Kris]

http://www.ebay.com/itm/Portable-LCD...wAAOSwFdtXw8~D

These keep getting cheeper and cheaper.

They also sell the inline ones.