• Is there any point in bringing the parameters of osmotic water down to zero?

  • Kellie

Hello, marine aquarium enthusiasts!!! I have been studying information about marine aquariums for several months, and everywhere I see that many strive to bring the readings of osmosis water down to zero (using ion exchange resins or passing it through a second membrane). However, I came across a topic, or rather a post from eight years ago, where one aquarist simply defended the idea of letting the water sit before salting it. I understand that his water might be soft. But what are the maximum acceptable TDS meter readings for water preparation in a marine aquarium???? I ask because I have 18 ppm after osmosis, and should I bother with further reduction????

Darrell7542

Can you tell me what is in these 18 ppm? I change the resin if the TDS is above 2, to avoid any doubts about the quality of the water.

Lindsey3628

So you are asking, or do you want to say something? There is no definite opinion about resins, but it is still calmer with resin.

Randall7906

I draw conclusions from the information studied, that's why I'm asking. The example I provided in the previous post. So, won't it be calmer this way?

Gene1948

I think you are a bit confused. The TDS meter does NOT MEASURE HARDNESS. It measures specific conductivity (i.e., the presence of ions from VARIOUS salts, not just calcium and magnesium compounds). For example, my reverse osmosis system even showed NITRATES after the membrane. And quite significantly (up to 10 mg/L). And I have no idea what else, I suspect silicates (I don't have a test for them). Naturally, it's difficult to deal with diatoms in water prepared on such a basis, to put it mildly. I installed resin yesterday (and it removes not only hardness, but also binds free ions of various salts), now let's see the result.

Jeffery7866

, +1 , osmosis does not remove nitrates and silicates, that's why resin is used. Mainly, Duox is used. And the idea of two membranes is complete nonsense; I can't imagine the setup, i.e., after one membrane, a pump needs to be installed to feed into the second membrane?

Katie3017

You are mistaken.

Elijah7048

Here is the table of osmotic water analysis and comparison. If those nitrates (zero) concern you and for complete water purification bringing it to zero across all parameters, there are special ion exchange resins – selective anion exchangers. After that, everything will be at zero. But for me, the indicators shown in the table are excellent for a combined reef.

Ricky9405

Provide an argument that I am wrong; I tested the water after osmosis, nitrates were up to 12.5, the same in tap water. Tetra test showed 0 after the resin.

Nicole

Forget your osmosis, that's the whole argument. Although... I'll go measure it. I measured, after osmosis nitrates = 0. TDS = 8.

Kyle

Well, they are not nitrifiers, but denitrifiers. They purify seawater from nitrates, and only from them, while the resin will extract everything that is needed and what is not needed. You should read a book about marine aquariums, for example, Savchuk's "Reef Aquarium" - many questions will be resolved.

David2398

What membranes do you have and what is the TDS value?

Lisa

Nitrates appear during the nitrification process directly in the aquarium.

Vanessa6144

Osmosis is not relevant here; in this case, it's the membrane, but I have only 17 ppm at the output, not 100 ppm, using a Filmtec membrane. There was a topic about this a couple of years ago, but I can't find the discussion about nitrates after osmosis.

Joseph1346

I take TDS testers and measure the tap water at home, which fluctuates between 246 ppm and 280 ppm. After purification with a regular 5-stage household reverse osmosis system, my water shows 002 ppm to 006 ppm. I use this water for both the sea and my family. When the water shows 008 ppm, I change the membrane. I don't have any resin, but I'm considering that issue.

Elijah7048

Are you changing it just for peace of mind or because some undesirable consequences are starting to happen in the aquarium?

Catherine

I change it to keep everything as good as it has been for many years, but if I hadn't changed it in time and had been adding water with 30-50 ppm and thought it would be fine, I believe I would no longer be involved with the sea, or at best, I wouldn't be admiring the reef but would be struggling and bothering everyone on the forum, asking why, and for help, advice on what to add, sprinkle, or put in, etc. For me personally, experimenting, and God forbid losing two marine aquariums with no parameters and everything else, is a complete disaster; it's scary to think about what that would cost. So, that's my answer to you, and it's up to you to think and decide how to proceed in the future.

Susan

If you install the resin, you won't need to change the membrane for a long time... The water in your tap is already almost perfect at 240-280 ppm; with that, you can easily reach zero with the help of resins for a long time... I live in Mirgorod - 1070 ppm in the tap, after osmosis with new cartridges it's 42 ppm, after the resin it was zero for a hundred liters, now it has reached 600 - TDS shows 11, in the aquarium it's now 9... If I had known, I would have bought more resin... I hope the startup will happen, and then... maybe I'll be running around the forum with my tongue out...

Jeremy

I bought a TDS meter, it shows 240 at the input and 175 at the output!!! Osmosis UST-M RO5. I bought it in an aquarium six months ago, with a double carbon pre-filter and a Filmtec membrane. How can it be that the filter works so poorly? Is the membrane defective? I will buy a new membrane and see how it filters.... I also want to buy resin. Please advise which resin filter is better to buy?

Stephen

Try to collect water directly after the membrane; maybe the 5th stage has a mineralizer that saturates the water with salts. If it's the same, you need to replace the membrane. You need to buy a separate flask and a removable cartridge. Fill the cartridge with resin and connect it to the output of the osmosis system. This person sells a complete set here on the forum.

Colin1418

I apologize for the silly post. It turns out I just connected the TDS meter to the wrong hose. It happens... Thank you.

Michael5242

I have been experiencing cyanosis for about a month, and I started looking for the cause. To my horror, I measured the TDS at the output, and it showed 90. At the input, it’s around 600-650. All the filters are new. The membrane is over a year old, so I understand it’s time to replace it. I am also considering resin.

Paul

Guys, I need help, I'm really confused!!! Here's the picture, where do I need to get water for the aquarium??? Thanks everyone...

Laura4892

With 4 filters (reverse osmosis membrane) of the blue tube.

Heather2018

Once again, right after the reverse osmosis, without a filter with some coconut flakes, right? I'm going to redo it now... Thank you. P.S. Is there pure osmosis in the expansion tank?

Gregory9432

Cool! Are there 3 membranes in the diagram?

Alan273

Well, actually, have you seen a reverse osmosis system? A silly question...

Patrick4439

You won't believe it, I've seen it. I've been using it for 5 years. In the diagram you provided, positions 4, 5, and 6 are all the same size and configuration; logically, these are the housings for the membranes - what is that? I found the source of the diagram on the website. It's a silly diagram. In reality, the post-filters and the membrane housings look completely different; in the diagram, they are the same. So, you haven't seen the system in reality.

Jesse3979

·4 stage: Membrane (operates on the principle of reverse osmosis) Microfilter Co., Ltd allows only water and oxygen molecules to pass through. It is the main component of the system. ·5 stage: post-carbon cartridge with high-quality activated carbon from coconut shell. It further purifies the water and enhances its taste. ·6 stage: mineralizer, contains mineral granules that dissolve in purified water and enrich it with essential minerals for humans.

Elizabeth

That's correct, there is reverse osmosis, but it's unclear how pure it is. For example, my TDS meter shows about 400 ppm at the inlet. After turning on the reverse osmosis, it immediately shows 50 ppm, and after a couple of liters have been drained, it gives 12 ppm. (If I had a tank, the average hardness would be about 30-40 ppm.) Therefore, I connected a resin cartridge at the outlet to bring the TDS meter readings to zero. If you decide to install a resin cartridge, you need to put in some kind of check valve to prevent water from the tank from flowing through the resin (due to the high flow rate, the water won't have enough time to be desalinated).

Dana4701

Yes, but if we don't use a tank, how much water will be collected? We don't have the 3 atm required for the normal operation of the membrane in our system...

Joshua

Then a system with a pump is needed. I have one installed. If there are no 3 atm, there may not be any leaks at all.

Kristen2246

I can't understand which valve and why... you install a tee at the output of the post-filter (not the remineralizer). The resulting hole is the path to the cartridge with resin, after which there is a tap from which we collect water for the sea.

Darrell5975

Like this, but drawn a little incorrectly; you need to cut in a tee and a valve between the fitting and the tee that goes to the expansion tank. Or just shut off the valve on the expansion tank (then you don't need to install a valve near the tee) so that water from the expansion tank doesn't flow back through the resin under pressure. Due to the rapid pressure, it won't have time to desalinate.

Amy9618

What feedback? Always 0, at most 3 ppm after the resin. I'm done. I'm tired of your over-chemistry.

Jeffrey

I set up 2 resin tanks for myself, so I will need to change them less often. Has anyone restored it (the resin)? What is its average mileage?

Melanie

DOWEX MB-50 resin is regenerated. The regeneration solution is 1-8% H2SO4, 4-8% HCl, or 4-8% NaOH. I read about it in its description.

Chad4168

Oh, I made a mistake. Totally off-topic.

Kathryn514

Can I have the link? Davex is already asking for three liters of the owner's hand... I want to make a large column for the experiment, using regenerate for it.