The Reef Tank banner

"seasonal affective disorder" for corals?

657 views 7 replies 5 participants last post by  richkor 
#1 ·
Would like the think tanker's ideas on a problem that occurs in the tampa area around twice a year. I'm not 100% sure this is the cause - but I do have a theory

Around twice a year - the water companies in the tampa bay area change from chloramines to chlorine to disinfect the piping. Around the same time, a lot of reefers report stn/rtn of their corals - usually base recession.

Here's my theory:
Honestly, the more I think about this - there may be something to "seasonal affective disorder" in corals related to the switch between chloramines and chloride disinfectants (sorry - seasonal affective disorder will be well known by northerners - its sort of a joke).

Maybe those of us that make our own water through our own RO/DI units (and have tanks less than 300 gallons to dilute incoming water) are more susceptible to the trace ions coming through or getting past our DI resin. there's no data whatsoever on real time water testing and what the water companies are sending us during this switch from chloramines to chlorine back to chloramines. The problem seems to occur just before the water is switched to chlorines or during the chlorine treatment. thats just too weird and coincidental.

I have no scientific explanation for it either - since ro/di units are supposed to be better at chlorines than chloramine. Maybe the extra chlorine is breaking things off the carbon blocks that are normally locked up when treating chloramine water?

Scientifically - I think I can come up with a scenario:
Let's say it's ammonia getting broken off the carbon block during this chlorine purge the water company does - it gets through your ro membrane - some of it (less than 1 PPM) gets through your DI resin. you could be dealing with 0.25 PPM ammonia in your saltwater mixing station and not know it. Your TDS reading on your RO/DI would still be zero.

OK - so you've got extra ammonia going into your aquarium - more than is normally produced by the fish and other livestock. It's not alot. it's not killing the fish. Its only an additional 0.25 PPM.

What happens next? Well, you've got extra nutrients that the bacteria love to consume. They are happy and they start "getting it on" and reproducing. Now you've got the imbalance of nitrifying bacteria to denitrifying bacteria (which probably take around 6 weeks to catch up). you may be in fact running a mini-cycle. The only way to tell is if you see a rise in your nitrates. The increase in nitrifying bacteria means a decrease in the available alkalinity. The decrease in alkalinity may stress corals (or some other mechanism may be at fault).

In some cases - if the rock is clogged with detritus and mulm - then the denitrifying bacteria can't re-populate inside the rock cause it's plugged up. the only place they may be is in the sand (if it's deep) in the display and maybe in the refugium. Properly designed refugiums are only taking on around 10% of total system flow through - so it's going to take longer for the nitrates to make their way to the refugium.

So here's a question or two to see if the theory holds:
Do you make water as you need it for a water change?
Do you have a holding vat for RO/DI output?
Do you buy your water from an LFS?

My thinking is: if you make 10 gallons at a time for a water change and use all of that 10 gallons directly - then you may be experiencing the above.

If however you have a salt water mixing station and your holding take is 100+ gallons - then the water you may make during the cross-over may not have an issue - as it can be properly diluted with the holding tank water (and/or have an opportunity to off-gas).

If you buy your water from an LFS - I think most of them have holding tanks greater than 100 gallons - so they are also unaffected by the cross-over.
this comes from this thread here: http://www.reefcentral.com/forums/showthread.php?t=2415936

The user's post regarding base recession is most likely a pest issue - but others are having similar issues.

So please feel free to share your thoughts. Does your region shock their systems with chlorine? are you seeing similar base recession when this occurs? what are your other theories on why it occurs once or twice a year?
 
#2 ·
If your RO/DI is producing zero, or real close to zero TDS, there won't be enough of anything in the water to cause a real problem. Any changes in the quality of source water would just effect how long our RO/DI filters last.
 
#3 ·
there's two points there however:

1.) zero tds doesn't mean there's nothing in the water. it's just not detected by the TDS measurement. you could still have anything in the PPB range (Copper, arsenic, ammonia) - but since it's below the detection limits - it reads zero.

2.) The assumption is made that the DI resin stage removes anything and everything not removed by the carbon blocks or ro membrane. Again, not true - see item #1. Also, TDS is only measuring conductivity. you could still have organics or other covalent bond molecules coming over that is not measurable by TDS.

"Enough of anything" is an interesting phrase you use. how can we be sure? If, for example, the chlorine treatment applied by the water companies is releasing copper from the pipes - and you let through 0.25 PPM of copper from the RO/DI unit (even though your TDS is measuring zero - 0.25 PPM is still less than the detection limit of 0 PPM tds) then you could be harming your reef tank, yes?
 
#5 ·
Can you get information from the tampa authorities as to when they do this? If so, I'd simply run the RODI unit and not keep the water to "flush" the system. This way you avoid using any potentially contaminiated water.

I have personally never experienced anything like this, but I also have a much larger tank and a new filtration station that my source water comes from...they boast it is the most cutting edge and efficient in the country, but I haven't looked into it in detail. No issues with the water, so I haven't worried about it.
 
#7 ·
Can you get information from the tampa authorities as to when they do this?
yes - all of the counties announce when this is occurring through mailings and on our bills. The LFS in the area also post bulletins to notify us.

It's just too much of a coincidence that well established reef tanks (with some very knowledgeable folks maintaining them) in the Tampa area have this disorder twice a year - around the same time as the switch. The switches usually occur in May and September.

I didn't want the discussion to drift to what to do at the moment but those are good suggestions. I would hope everyone who runs their own RO/DI would always flush out the first 5 minutes of RO output to avoid the RO creep. it does indeed save your DI resin bed. I would also hope that they buy quality sediment and carbon blocks.

I'm extremely curious if my theory holds: what happens in a RO/DI system when the source water changes? What downstream effect can this have?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top