LOST on what is wrong

[DHC]

I have a 150 gallon tank. It was doing fine until about 2 months ago. Corals started to die off. I tested for all parameter again and again, Ammonia, Nitrate, Nitrite, Phosphate, Magnesium, Alkalinity, Calcium, Salinity. All were normal.

The only indication of something wrong was the ORP reading. It used to be around 300 to 350 easily, but now, for the life of me I cannot get it go beyond 300. Most of the time it's around low 200. I bought a new monitor thinking the old one might be defective, that did not help either.

I changed water on a weekly basis. 20 to 30 percent when I know something is wrong. That did not help.

I am at the end of my wit. I apprecaite an input. Thanks.

[JoeMack]

You mentioned ORP, but do you use ozone or UV?

We need more info.

[DHC]

Yes, I use Ozone. Currently it's not running. I have the Ozone set as high as 100 Mv and it made no difference. I set it at 60 and after 24 hours, the reading remain at 180 to 200. I moved the probe to different position; in the sump; in the tank. It read about the same.

I calibrated the probe and cleaned it. The replacement probe showed about the same reading.

I have carbon in the system, thinking that might help, but it did not. I have a Euro Reef Skimmer. A chiller set at 81, 3-250 watts MH and 2-140 watt VHO.

There are about 250 pounds of LR. I have only 5 fish and about 7 to 8 LPS. I would say this is a fairly light bio load

The water source is from a 5 stage RO-DI unit. I tested the output water using a handheld TDS meter and it registered zero.

[ReeferMac]

Calibrate your refractometer? I was having 'issues' in the tank, and on a whim checked that... had drifted 0.004. Worth a look. I just used RO/DI water to cal. to Zero.
New bag of salt?
What's your calcium supplement? New batch of that?
New food? What changed 2-months ago?

- Mac

[DHC]

I calibrated the refractometer, just like you did, I use RO water. It was a bit off not not enough to justified the change.

I did open a new bucket of salt but I am pretty sure it was after the change. Besides, if the salt was screwed up, shouldn't it show up on my testings?

I use Geo Calcium reactor and it's still the same media before the change occurs.

The new additions is a chiller, which I cannot see why that would cause it. I also added 5 turbo snails recently to control the turf algae.

I appreciate all the suggestions. Like I said I am simply out of idea what might cause this. I covered everything I can think of......

[chrisaggie]

wow, we will need a LOT more info to help you figure this out:lighting, any dosings, feeding, livestock, filtration, etc...
~Chris

[kevin dd]

Does the water go through copper tubing on that there chiller?

[chrisaggie]

I din't believe there are any aquarium chillers made with copper pipe. I think companies are smarter than that.
~Chris

[NeilPearson]

Do you have a DSB? How old is your tank? I ask because I saw you registered in Feb 2002.

If that is when your tank started and you are running a DSB, you look right on schedule to have it going wrong.

Do some searches on DSB and OTS (old tank syndrome)

[wave_happy]

DHC,

Just a few questions . . .

Can you give the actual readings of all of the tests as well as the test kits used?

You do not mention the pH reading? pH could be depressed by the house being closed up for air conditioning. You mention an "algae problem", a heavy algae load could lower the pH to a critically low level after lights off. pH readings should be taken just before lights on and just before lights off.

I would not rule out a bad batch of salt.

How do the ORP and other readings register on newly mixed salt water?

What types of corals died off? What did they look like before they died? How long did you have them before you started losing them?

You added a chiller and the thermostat is set to 81 degrees. What is the actual temperature of the water?

Do you have a grounding probe(s)? The new chiller may not be properly grounded.

Has the house, gardens nearby or pets been sprayed with pest/herbicides?

Any chance of "unknown foreign objects" in the system? During a family gathering I caught two of my nephews taking turns dropping pennies into my freshwater tank from the upstairs balcony.

[easttn]

Is your water grounded, stay voltage perhaps.

[chrisaggie]

Wow, there are really a millions things that could be wrong, very very hard to say unless we did a detailed study of the tank.

[DHC]

Yes. I have a DSB. The tank was setup about 6 to months ago. I changed from 75 gallon tank to 150. I took these reading on Thursday evening. I always change water on Friday night. Test kits are Slifert

Ammonia is zero

Nitrite is zero

Nitrate is zero. I know, this is almost not possible, but I use the more sensitive measurement and the result liquid is all white.

Salinity is around 1.024 to 1.025

Mag is the fluctuating one. I have been manually adding it. The reading is typically around 1200 after water change, and I add it daily to bring it up. Last measurement was around 1300. I stop adding it for about a week now.

Ca is between 400 to 420

Alkalinity is between 9. and 10

PH is at 8.0 to 8.3. I measured this numerous times and it is fairly consistent

Temperature is around 81, depending on if the chiller kicks in or not. I have a Medusa and another independent thermometer and they all confirm the temperature is within 1 degree of each other.

I never did test the newly mixed saltwater. I do always take measurement after the water change and the reading is about the same as these I am providing now. I never did get an ORP reading on the new saltwater. I will look at it. I am doing a massive water change tonight. Most likely around 40 to 50 gallons, maybe more.

The corals that died were clam, frog spawn, hammer, and some snails. The remaining corals are "unhappy". They are about 80% closed up. The fish are fine and so are the anemones. The corals were fully extended and in really good shape. I had them for 3 to 4 months. When the coral died, I did not leave it in the tank. As soon as I see sign of decay, I pull the coral.

I do not have a grounding probe. I was wondering about that.

I feed fairly light, no more than 2 or 3 times a week. I manually feed the fish and the inverts. I do not just throw a bunch of food in. I do feed home grown Planktons about once a week. I stopped that for 2 to 3 weeks and it made no difference.

I live alone and no pet in the house. So foreign object can be safely rule out.

The return pumps are Mag drive 24 and 18. The water hose? I changed the hose from the clear one to the UV resistive black one to reduce algae growth… The hose came from Marine depot and it was changed around May..... Hmmmm...

I also change to different material filter sock. I thought that might be it so I put back my older filter for a week, that made no difference.

Like I said, the only thing that indicates there is an issue is the ORP reading. It's been hovering around 250….

Thanks for all the inputs!

[jdieck]

As you know low ORP = High organics. Because your biuo is light and your feedings are relatively small the only think based on yoiur information is that the new hose is releasing some manufacturing chemicals inot the water. Try Vinyl (Ideally Tygon). Ozone will not be a problem as if you are injecting it trough the skimmer it will be fully reacted by the time it reaches the vinyl. Remember that UV resistance is not necesarely O3 resistant so the Ozone might also be motivating this release from the black hose.
I use Neoprene (black O Rings in my skimmer flanges and every time I sweep clean them there is black stuff released due to Ozone attack.

[DHC]

The ozone is injected into the skimmer and the output also ran through some carbon. I do not smell ozone ins the air. So I think the ozone is not reaching the hose.

The hose is design for aquarium and came from large supplier like Marine Depot. I would like to think the hose is safe.....

[easttn]

If any of your fish start showing any hint of lateral line disease, get a grounding probe. Prolly ought to get one anyway.

[jims47]

I realize you feel the hose is safe, but if it where me I would contact them via their 800# and ask if they have any tech info on the reaction of it with ozone. You may get a quick answer and be able to check that possibility off your list at any rate.

[DHC]

Thank you for the suggestion. I never did find out what the cause was. I started doing massive water changes, 50 gallons per week for the pas 2 weeks. As of now, my system is about 80% recovered. Meaning the bubble is fully open, the flowerpot is fully extended, the pipe organ is slowly opening again. Now if I canonly get my 2 frogspawn is fully open.....

I think it's only 80% because the remaining corals were "damaged" from the trauma and may take much longer to recover, or may never recover...

[ShipMate]

Sorry to hear about the coral damages. Temp spikes seem to be a common source of coral deaths/bleaching. Dying sponges have been known to cause severe stress (or wipe outs) of tanks.

I use a digital thermometer that records highs and lows. A good investment imo. But it seems you have that under good control.