RODI/TDS question
- Thread starter biecacka
- Start date
OrionN
Moved on
Looking at the numbers you posted, I think your RO membrane is no good. A good RO membrane set correctly rejected about 98% of the TDS. I always spend a little more money and buy the premium membrane from Spectrapure. They can sell you an untested membrane, or they test and confirm the rejection rate of their premium membrane.
Your membrane, assuming that the reading you have is correct, only rejected about 92.5% of the TDS (13/175=.07429) which is way too low.
Your membrane, assuming that the reading you have is correct, only rejected about 92.5% of the TDS (13/175=.07429) which is way too low.
OrionN
Moved on
Copper or brass (mainly copper) pipes after water softener is bad for our reef tank. Soft water is essentially slightly salted water. The salt will corrode the copper tube and will give high copper in the water. Still a good maintain RO system will remove essentially all copper from the water.
jason2459
Well-known member
Essentially but not all. That's where the DI comes in.
OrionN
Moved on
Did you know that natural sea water contain about 10 ppm of copper? (about 10 mg per cubic meter of water).
I use tab water in my office tank to mix salt water for years without problem. I do use RO for top off water in that tank.
DI is not needed for reef tank.
Certainly in the OP RO/DI out put of 2 ppm is not a problem, nor it cause high nitrates in his tank.
I use tab water in my office tank to mix salt water for years without problem. I do use RO for top off water in that tank.
DI is not needed for reef tank.
Certainly in the OP RO/DI out put of 2 ppm is not a problem, nor it cause high nitrates in his tank.
Last edited:
jason2459
Well-known member
Again misleading. Seawater copper is mostly chelated, bound by organics. There's also many sources of copper that adds up in our tanks.
This is a good article with a focus on metals in the reef systems and highlights copper quite a bit.
http://www.reefkeeping.com/issues/2003-04/rhf/feature/index.php
I prefer to say RO, RO/DI may or may not be required all depending on what is in the Tap and what is making it past the RO membranes. I do not disagree that for some straight tap could be just fine. I do not disagree that RO alone could be more then adequate for some. But for some the DI stage could be necessary.
I also agree I don't think Corey's problem is related to the RO/DI unit. Unless it is...
Last edited:
OrionN
Moved on
There is nothing misleading about it. We know that freshly mixed, completely dissolved salt water at right salinity and temperature is toxic to animal life. It is though that part of this toxicity is the heavy metal in it is not completely chelated. A lot of the copper are chelated and detoxified in our tank, they also take up by various organisms and plants (which required them for health)
My point is that copper is not a killer ion that you need to keep at 0.
My point is that copper is not a killer ion that you need to keep at 0.
This article goes over what's in seawater:
http://reefkeeping.com/issues/2005-11/rhf/index.php#7
Copper generally will be well less than 1 ppb. 10 ppm is more than enough to kill a lot of invertebrates, which can start dying at 10 ppb. Searching will turn up a lot of articles on copper toxicity.
Many people get by with RO systems, or even by using tap water with chlorine or chloramine treatment. Others aren't so lucky, or are lucky only for some period of time. For example, cities sometimes treat water for a few days with anticorrosives, which often are zinc-based and extremely toxic.
http://reefkeeping.com/issues/2005-11/rhf/index.php#7
Copper generally will be well less than 1 ppb. 10 ppm is more than enough to kill a lot of invertebrates, which can start dying at 10 ppb. Searching will turn up a lot of articles on copper toxicity.
Many people get by with RO systems, or even by using tap water with chlorine or chloramine treatment. Others aren't so lucky, or are lucky only for some period of time. For example, cities sometimes treat water for a few days with anticorrosives, which often are zinc-based and extremely toxic.
jason2459
Well-known member
Just not something I agree with. TDS readings at any level could be fine or could cause problems. Copper is just one thing and something I personally know is in my water at troublesome levels if not removed. Chloramines would be another problem among many other things. Luckily I don't have to worry about chloramines.
jason2459
Well-known member
I don't disagree with that. :beer:
biecacka
Active member
I'm not suggesting that my RODI is my nitrate issue either. A LFS near me, who services tanks said on a scale of 1-5 my RODI output is a 3. I'm aware at my issue is multi leveled. 30 fish in the tank, 4 cubes a day, no skimmer for 2 years to name just a few. My skimmer is now online and working great, I'm dosing carbon and getting this under control. My original question was to check the validity of the LFS suggestion as it seemed strange to me that my 2 reading output could be such an issue.
Corey
Corey
jsspallina
New member
Your RODI is not the problem...
mechanically removing algae and detritus from your tank combined with water changes and an operational skimmer will effectively lower your nitrates and provide overall better conditions for your fish.
however any copper or other medications you put in your tank will be removed by your skimmer.
jsspallina
New member
carbon dosing is very effective at lowering nitrates but i would strongly consider running bio-pellets over vodka dosing.
biecacka
Active member
There is NO algae in the tank. None what so ever. The nitrates are high and corals are upset. But they are looking better which hopefully means they are coming down. I just built an ATS so that'll be online soon to play with as well. Should be interesting. Guess I'll probably limit myself to 2-3 more fish and too out at 32-33 for the tank. The new skimmer is handling 30 fish like its nothing. Like its a light bio load :lol:
Not to mention, nitrates don't really bother fish to much, look at most predator tanks. But I am doing it for the coral. The fish are healthy and such-maybe just a bit upset I cut their feedings in half!!! :lol:
As stated, I was more curious from the chemistry aspect how valid the serviceman from my LFS was in his point. I had never heard that before. Reduction in nitrate had started prior to him and I having a conversation. TMZ helped me come up w/ a dose to start with and we have seen improvements already. It's just a slow process like everything else in this hobby-not necessarily a bad thing either.
Corey
OrionN
Moved on
The fish load and no skimmer for the last 18 months certainly is the problem. You just going to get back on the ball and do some maintenance. I am sure improve export will help the nitrate. IME, nothing beat the need to do regular water change like you start to do.
I keep large tank since 1999. 450 gal DT with additional volume sump and refugium. That first tank was not well though out. I did not have the space to mix and change water. Maintain it was a PITA. I learned a lot from that tank. Now 50 gal water change for me is turn a valve, self stop at certain level. Close the valve and pump in water.
Best of luck in get your tank back to reef shape.
May I inquire on your list of fish in your 240 gal DT? And you want to add more?
I keep large tank since 1999. 450 gal DT with additional volume sump and refugium. That first tank was not well though out. I did not have the space to mix and change water. Maintain it was a PITA. I learned a lot from that tank. Now 50 gal water change for me is turn a valve, self stop at certain level. Close the valve and pump in water.
Best of luck in get your tank back to reef shape.
May I inquire on your list of fish in your 240 gal DT? And you want to add more?
biecacka
Active member
Purple and yellow wrasse
6 line wrasse
Yellow tang
Sailfin tang
Purple tang
Blue tang X 2
Clownfish X 3
Purple dottyback X 2
Flame angel
Coral beauty angel
Starry blennie
Bluethroat trigger
Multi color lubbocks wrasse
Melanurus wrasse
Lamarck angel
Foxface
Yellow watchman goby
Female swallowtail angelfish
Fire fish x2
Golden head sleeper goby
Diadem dottyback
Bicolor dottyback
Scribbled rabbitfish
Melanurus wrasse (female)
Filamented flasher wrasse (male)
Checkerboard wrasse.
I would like to add 2-3 more maybe. But likely won't and definitely not until I get this under control. The water is already in better shape so some water changes and the carbon dosing is helping as is the new skimmer.
Corey
6 line wrasse
Yellow tang
Sailfin tang
Purple tang
Blue tang X 2
Clownfish X 3
Purple dottyback X 2
Flame angel
Coral beauty angel
Starry blennie
Bluethroat trigger
Multi color lubbocks wrasse
Melanurus wrasse
Lamarck angel
Foxface
Yellow watchman goby
Female swallowtail angelfish
Fire fish x2
Golden head sleeper goby
Diadem dottyback
Bicolor dottyback
Scribbled rabbitfish
Melanurus wrasse (female)
Filamented flasher wrasse (male)
Checkerboard wrasse.
I would like to add 2-3 more maybe. But likely won't and definitely not until I get this under control. The water is already in better shape so some water changes and the carbon dosing is helping as is the new skimmer.
Corey
Similar threads
