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View Full Version : My RODI is not working and SPS coral is dead/dying...is there a connection?


newreefer_59
02-19-2013, 07:31 PM
Since December, I have only been in my home about every 2 weeks, and the lady in there now (long story) is caring for the tank with weekly water changes. She was not adding enough salt initially and the SG was at about 1.020, last month. I had her bump up the salt little by little and now it is up to 1.025. In the meantime, almost all of the SPS coral has died or dying and there is purple-ish growth over some area of the tank bottom, as per pic.

Now I notice the RODI TDS meter is displaying water out about 150, when water in is about 170. The water out used to be around 0!! I changed the carbon and sediment filter just now (after 6 months) and the DI filter is scheduled for April. Would the high TDS be killing my SPS coral? All fish seem very healthy. It is a 150 gallon tank with T5 lights, and skimmer seems to be working fine, etc. Any thoughts?

kien
02-19-2013, 07:40 PM
Where are the rest of your parameters at?

Phosphates
Nitrates
Alk
Calc
etc..

If your SPS were used to nice clean water with a TDS of 0 but are now being exposed to non zero TDS water they could definitely be disgruntled enough to pack it in and call it quits.

newreefer_59
02-19-2013, 07:59 PM
ph 8.7
Calcium 420
Kh was 10

that was my thought re: the RODI, but wondering why it is not 'cleansing' the water now. I replaced the DI last July and the RO membrane in July 2011.

sphelps
02-19-2013, 08:03 PM
Usually it's a combination of a few things that end up killing coral. High TDS in make up water, salinity fluctuations, and likely a few other factors are likely all to blame. Purple growth is a form of cyano, type of algae/bacteria film.

kien
02-19-2013, 08:05 PM
ph 8.7
Calcium 420
Kh was 10

that was my thought re: the RODI, but wondering why it is not 'cleansing' the water now. I replaced the DI last July and the RO membrane in July 2011.

Do you have it on an auto shut off of some sort or do you manually shut off the source water by turning a valve ?

newreefer_59
02-19-2013, 08:33 PM
and is sent up via PVC pipes to
a) top off the tank
b) perform water changes

kien
02-19-2013, 08:40 PM
and is sent up via PVC pipes to
a) top off the tank
b) perform water changes

Sorry, I'm not sure I understand the setup here. So, do you have your RO/DI output running straight into your ATO reservoir ? Or is the RO/DI output running into another reservoir for water changes and ATO? Is there a float valve in the RO/DI reservoir? If there is a float value then is that your primary means of shutting off the RO/DI when the reservoir is full? Do you ever turn off the source water going into your RO/DI?

The reason I ask is that if for example you have your RO/DI output going into a reservoir that has a float valve to shut off the water, you should not rely on your float valve as your primary means of shut off. Water will evaporate out of your reservoir throughout the day and case the float valve to drop causing your RO/DI to kick on. This will happen several times a day and this constant on/off cycling of the RO/DI will burn out your membrane prematurely. Instead, you should turn off the source water going into your RO/DI unit whenever you are done making up water and only turn it on again when you need to make more water.

newreefer_59
02-19-2013, 09:03 PM
...and then I turn the RODI off until new water is needed. Thanks.