And why you want it to be 0 TDS? What's the difference between around 5-10 ppm TDS (a rather normal result after RO) and 0 ppm TDS?
Sincerely Lasse
nitrates
- Thread starter reef4life!!!
- Start date
- Tagged users None
Sincerely Lasse
nldemo
Active Member
I think 0 TDS is what is going to get you as close to true clean seawater as possible.
RO is good enough for us to drink, but to try and emulate pristine seawater for my fish babies i would use only the best, 0 TDS. They will get plenty of tds produced from feedings.
RO is good enough for us to drink, but to try and emulate pristine seawater for my fish babies i would use only the best, 0 TDS. They will get plenty of tds produced from feedings.
What exactly is TDS? What it is - exactly - a TDS meter read and report as TDS to you? And why is TDS higher than 0 in the RO water dangerous for your fish babies? Do you know the TDS value in fresh newly mixed saltwater - before any biological processes?
Sorry @reef4life!!! if it seems that this discussion is of topic - it is not - because if you really know what TDS is - especially in water from a RO equipment - you would not bother as long as it is below 10.
Sincerely Lasse
OP
OP
reef4life!!!
Active Member
well no problem...i am learning from this replies too..also for now i just want my nitrates to added water to be lower than 10..i don't care if its 10 or 0...if i see that 10 is too much i can switch
nldemo
Active Member
Yes, you definitely don't want to be adding nitrates into your tank from your clean water source. That should be 0 nitrates for sure.
As for the TDS, it is true that you should be fine with TDS lower than 10. With an RO/DI system, you will be guaranteed a TDS of that all the time. Not true with a normal RO system. I change out my drinking water filters yearly and my TDS is much higher than 10 by that time. With a DI filter, you simply need to change that out once your readings start increasing past zero. Even better is if you have two DI filters in series, then you can simply take the 2nd filter out and replace the first filter with it. Likewise, with two TDS meters you can be sure you've truly exhausted that DI resin in the first filter.
I'm sure most of us in the hobby don't have true dedicated fish rooms. We use a space in the laundry room (guilty), or a basement, under a sink somewhere... It is not much work to setup an RO/DI, not a big expense, and easy to use. Much easier than changing something after it has already entered your tank.
Straight from google: TDS stands for total dissolved solids, and represents the total concentration of dissolved substances in water. ... Common inorganic salts that can be found in water include calcium, magnesium, potassium and sodium, which are all cations, and carbonates, nitrates, bicarbonates, chlorides and sulfates, which are all anions.
While some of those things measured in TDS can actually be beneficial for our tanks, we get the right mix of them already from our salt mixes. The others can be harmful to our tanks, and will get produced naturally through feedings and fish waste. So why add them in with our water when it is so easy to remove?
Just my $.02 ... not something I would go to war over, just something that I think is a super low hanging fruit and no reason to mess with. To be fair, I once met a guy who only used water from his hose to top of his tank and his fish seemed alright. But my goal is to have these fish thriving, not just alright.
OP
OP
reef4life!!!
Active Member
ok so i wanted to ask this..when i get my RODI system how often i must change the filters or anything else in the system? do i have to replace only the filters once in 6 months,do i have to change more than just the filter and how often?
nldemo
Active Member
DI resin will depend on how much water you make and how often. I probably normally replace those every 6 months. The other filters (carbon and sediment) are fine on a yearly cycle, the RO membrane itself is fine every couple of years. 
Look for a system that doesn't have too much waste water. Mine is 1:1 ratio of good to waste, but I know many are much worse ratio than that.
Look for a system that doesn't have too much waste water. Mine is 1:1 ratio of good to waste, but I know many are much worse ratio than that.
IMO - TDS is one of the most idiotically parameters that we use int reefing hobby and it says nothing. Its only a calculating from the conductivity of the water. A TDS meter is a simple conductivity meter there the real SI- unit Siemens/meter is converted into some strange unit named TDS and expressed in ppm. The conductivity of the water is only depended on the ion strength of the water. It will not measure non-ionic molecules like aminochlorines and different gases. The normal calculating factor is the result in µS/cm * 0.64 and it is an average factor. To know the exactly factor you need to know exactly which ions you have
However there is few ions that will pass the RO membrane with exception for the Si and the silicate ion. There is - IMO - a myth that the Si and silicate itself cause diatom outbreak (because they need Si for their shell) However - we know today that most reef aquarium have Si concentrations between 100 - 200 µg/L or more. The Si comes from the limestone and from the coral sand used in our aquariums. With this knowledge the low concentration that can come from water reporting below 10 - 15 µ/cm does not matter.
And further on - with use of both anion and cation resins in order to get ultra pure water and after that mix it with salts that´s vary between industrial to food grade in purity is to make a fire for the crows - nothing else IMO.
Yes - if you have a waste ratio of 1:1 - I understand your use of resins. Normal ratio in 20 degree C for a good working RO membrane is around 1:2 to 1:3 (1 part RO water - 2 - 3 parts wastewater)
Sincerely Lasse
However there is few ions that will pass the RO membrane with exception for the Si and the silicate ion. There is - IMO - a myth that the Si and silicate itself cause diatom outbreak (because they need Si for their shell) However - we know today that most reef aquarium have Si concentrations between 100 - 200 µg/L or more. The Si comes from the limestone and from the coral sand used in our aquariums. With this knowledge the low concentration that can come from water reporting below 10 - 15 µ/cm does not matter.
And further on - with use of both anion and cation resins in order to get ultra pure water and after that mix it with salts that´s vary between industrial to food grade in purity is to make a fire for the crows - nothing else IMO.
Yes - if you have a waste ratio of 1:1 - I understand your use of resins. Normal ratio in 20 degree C for a good working RO membrane is around 1:2 to 1:3 (1 part RO water - 2 - 3 parts wastewater)
Sincerely Lasse
OP
OP
reef4life!!!
Active Member
So, is this white color what my rock must look like? Nitrates again pretty high and phosphates around 1 ppm.. (photos not great but there are parts on my rocks that are white instead of brown...i also see green algae in some parts ). Could this be a sign that my brighwell bacteria I added starting to work or this is a work from my fishes grazing routine (which they have gone crazy since I started to feed less)
You can check that - if the white is pure rock - your fishes does their job - if the white disappear when you touch it - it is bacteria film and not so good. I think it is rock and your fishes does exactly what they should.
Sincerely Lasse
nldemo
Active Member
I agree with Jesse. It is hard to tell from the photos alone what the white is. Could just be the surface of the rock poking through -- it would make sense with all those algae eating fish you have in the tank.
Your goal end state is to have the rocks covered in a nice coralline crust (the pinkish purple color). This is easier said than done because it requires the bad nutrients to be pretty low (otherwise the nuisance algaes will pop up) , the good nutrients to be sufficient enough (eg calcium), and proper flow & light. My tanks are ~10 years old and I have a good amount of coralline coverage on my rocks (>50%) ... but it's never been perfectly complete coverage for me.
Your goal end state is to have the rocks covered in a nice coralline crust (the pinkish purple color). This is easier said than done because it requires the bad nutrients to be pretty low (otherwise the nuisance algaes will pop up) , the good nutrients to be sufficient enough (eg calcium), and proper flow & light. My tanks are ~10 years old and I have a good amount of coralline coverage on my rocks (>50%) ... but it's never been perfectly complete coverage for me.
