• Rainwater

  • Judy

Good day to all sailors! I would like to inquire whether rainwater can be used as a substitute in a marine aquarium. I'm asking because when I tested the TDS of the rainwater, it showed 5, while the osmotic water showed 20, so I'm wondering if it's cleaner? The other tests for KH and GH showed zero. But I've heard that it contains a lot of microbes and can make the inhabitants sick; is that true?

Nicole7122

A TDS meter can only be used as a way to check how much the membrane is "clogged." That is, if the input is 200 and the output is 20, but it was previously 0-1, then it's time to change the membrane. In my opinion, rainwater will always be far from distilled water.

Lindsey3628

I don't know what you used to measure the parameters, but rainwater has a KH and GH of about 3 degrees; I checked it myself, and it's mentioned in the literature as well. In my time, I used such water in a planted aquarium when I didn't have reverse osmosis.

Holly

The pH tests show everything at zero, I just double-checked that the osmosis is zero, the rain is O, the rain pH is 6.5, and I checked the tap water KH is 12.

Kimberly2102

It seems like it's clear how to collect it! I went to a friend in the summer to check the rainwater collected from the roof, and it showed everything at 3, but I collected some in winter from a tarp, and it showed zero. BUT THE QUESTION IS whether it can be used for substitutions?

Erica

Apparently, winter rain is not the same as in summer.

Jennifer

Check the pH again.

Helen

PH 6.5

Joseph9203

So no one gave an answer... I have 60 after osmosis, and to achieve 0, I need a mountain of resin. I also recently checked rainwater - it was 5, and even 4. I might try it because the cyanobacteria are really annoying - they just won't go away. Probably some kind of junk is getting in with the water, which is what it's feeding on...

Alicia5489

So here's what to say. When it comes to osmosis, think about rainwater. It's easier to fix problems with the osmosis system than to chase after rain clouds. With the proper installation of a normal membrane, with source water of medium hardness (420-450), the output should be up to 10 at most. If the membrane is definitely in good condition and hasn't been used for years, one of the likely reasons for high TDS (over 10) is the connection of the system using a mineralizer. The mineralizer should be excluded from the system when preparing water for a marine aquarium.

Christopher4125

Depending on the membrane and water pressure in the plumbing, you will get different TDS values. When I was figuring out water purification for myself, I conducted several different experiments. I tested Filmtec membranes 50g, 75g, and 100g. To achieve the minimum TDS, you need a membrane with the lowest capacity. Currently, the 50g membrane is available on the market. The water in our local plumbing is quite hard, with an incoming TDS of about 400, and I get 15 at the output, but the water pressure is not high. When I installed an inlet pump (recommended for 50G membranes), the output was 7. I would not use rainwater.

Karen2578

Unfortunately, in Mirgorod, the water in the plumbing is 1500-1700, so with a membrane performance of 95-96%, it results in 60... has anyone installed another membrane in series? How can it be set up from a technical standpoint? I also wouldn't use rainwater if I had such indicators of 7... I haven't used it yet, but as an option, 5 is still better than 60.

Chris

I agree 100%, I've been at TDS 25 for a year and it's fine; if you're struggling with cyanosis, you need to look for the cause elsewhere... and zero TDS won't help.

Kimberly4253

TDS should be 0 after the resin. Some people might be fine with a TDS of 50, while others might have algae problems at 10...

Shane

Actually, the topic is about rainwater, and the direct request is to express an opinion specifically on this matter, not about what someone should do. If after osmosis the result is 60, how can we achieve 0 with resin? Should we connect 10 flasks in series? Let's respond correctly to the questions asked.

Wendy2244

I tested the rainwater for nitrates - 2 mg/L...

Michelle

30-35 TDS = 1 degree of hardness. I don't understand what you want - to breed fish or to fool people?

Erin

Do professionals no longer use activated charcoal for cleaning?

Leonard

What tone is that? You must be confused... sleep it off.

Katie5500

Since I can't buy a second OSMS right away... for a month I've been adding rainwater through a column with ion exchange resin, by gravity, about 50 liters, I haven't noticed anything bad so far, the pH has decreased from 8.5 to 8.2... using it constantly probably carries some risk, but if I were to run it through the OSMS, that might not be a bad idea, although it's too much hassle to collect the water, connect it, etc.

Wendy2244

Make sure to check the pH, as acidic rains often occur in industrial areas, which have a pH of less than 5. Additionally, rainwater contains significant amounts of sulfur compounds, mainly in the form of sulfur dioxide. I won't even mention the presence of mercury ions, iron ions, and chromium in rainwater. It is very difficult to determine this with tests, and adding such water to the aquarium leads to the accumulation of undesirable elements in live rock, sand, and at some point, all of this can be released into the aquarium. So it's up to you to decide, but I wouldn't recommend using distilled water in a marine aquarium.

Alexander

Thank you... I considered DW as an alternative when there are no other options - well, if after OSMOS 50, and DW-5, that's ten times less chance to mess up, right? Today another OSMOS arrived, I will set it up in sequence... I hope this will solve my problem with the high RPM reading.