Is 10 ppm TDS ok?

[Indiana Jones]

I recently got a new tank, and bought an AQUATICLIFE 4-Stage Reverse Osmosis Water Filtration Deionization System, RO/DI Filter Unit 100 GPD from Amazon. My TDS meter just came in today and my tap water is ~250ppm and the filtered water is 10 ppm. I already have my salt mixed and started the fishless cycle with Dr Tims one and only. I plan on getting some better filters soon, but is this ok for now?

 

[blaxsun]

Opinions seem to vary quite a bit on this one. Most say 0 TDS for SPS tanks, others say 1-2 TDS is perfectly fine - still others say up to 20 TDS.

The best suggestion I found was to add another DI stage to further polish the water. Sorry I couldn't be more helpful. Hopefully you'll get some additional suggestions as well.

 

[Woodyman]

Opinions seem to vary quite a bit on this one. Most say 0 TDS for SPS tanks, others say 1-2 TDS is perfectly fine - still others say up to 20 TDS.

The best suggestion I found was to add another DI stage to further polish the water. Sorry I couldn't be more helpful. Hopefully you'll get some additional suggestions as well.

The TDS value isn't as important as the content of the TDS.

For example if that TDS is all Ca or Mg, it's not really going to be an issue.

However, Si and PO4 are loosely bound up within DI resin and are usually the first things leaking through, can be NH4 as well though.

As @blaxsun said add a second DI canister to help polish it down.

Are you on well water? If so it may be better to buy 2 additional housings to run separate beds of DI instead of a single or double mixed bed setup.

In the future by the higher quality filter cartridges either from Spectrapure, BRS, Salt Water Aquarium, a big box store, etc.

 

[Indiana Jones]

Thanks for the replies. Right now it will just be fish only until the tank matures a bit. I’m on city water. I’ve only ran about 60 gallons through the unit and I noticed the sediment filter is turning yellow already. I think they might just be cheap filters?

 

[Woodyman]

I recently got a new tank, and bought an AQUATICLIFE 4-Stage Reverse Osmosis Water Filtration Deionization System, RO/DI Filter Unit 100 GPD from Amazon. My TDS meter just came in today and my tap water is ~250ppm and the filtered water is 10 ppm. I already have my salt mixed and started the fishless cycle with Dr Tims one and only. I plan on getting some better filters soon, but is this ok for now?

Will it be ok to cycle and setup your tank? Yes. You may get some extra algae growth or diatom growth depending on the content of that TDS, but it will be ok to use for the time being. You'll want to address it before stocking with corals however.

Some people cycle using tap water, and some people have successful reefs using tap water. It all depends on what's in the water.

 

[vetteguy53081]

Reason i dont like these units. They seem less effective than traditional 3-4 stage units.
As we are talking about total dissolved solids in water, an acceptable TDS level for a reef tank sits between 0 and 5 ppm. The goal is to get as close to 0 as possible. The higher the TDS number, the greater the chances are that issues will arise in your tank. A higher level of TDS can feed algae and harmful bacteria, inhibit the photosynthesis process, and negatively impact the immunity of your fish.

 

[Lost in the Sauce]

Can you check between stages? Although it will exhaust very fast, brand new DI resin should be putting out 0tds.

Something doesn't sound right here.

 

[Woodyman]

Thanks for the replies. Right now it will just be fish only until the tank matures a bit. I’m on city water. I’ve only ran about 60 gallons through the unit and I noticed the sediment filter is turning yellow already. I think they might just be cheap filters?

The yellowing isn't generally cause for concern. They change color quicker than they go bad. They typically last several months even if they have completely changed colors.

60 gallons isn't a lot though.. but that very well may be cheap DI resin. Get a higher quality resin for the future and that should make the difference.

Another thing ensure you flush the unit of TDS creep on startup. Otherwise you will prematurely kill resin as well.

 

[exnisstech]

mine is always 0 tds after di stage unless my resin needs to be replaced

 

[Indiana Jones]

The yellowing isn't generally cause for concern. They change color quicker than they go bad. They typically last several months even if they have completely changed colors.

60 gallons isn't a lot though.. but that very well may be cheap DI resin. Get a higher quality resin for the future and that should make the difference.

Another thing ensure you flush the unit of TDS creep on startup. Otherwise you will prematurely kill resin as well.

I followed the instructions and ran the unit for 30 minutes before adding the DI filter, but maybe I made a mistake somewhere. I know this unit is on the cheaper end so the filters probably aren’t the greatest.

 

[Woodyman]

I followed the instructions and ran the unit for 30 minutes before adding the DI filter, but maybe I made a mistake somewhere. I know this unit is on the cheaper end so the filters probably aren’t the greatest.

30 minutes may or may not be enough.

Depends on the quality of the membrane, how it was shipped/packaged (wet or dry) and if they used any preservatives on it.

 

[Woodyman]

I followed the instructions and ran the unit for 30 minutes before adding the DI filter, but maybe I made a mistake somewhere. I know this unit is on the cheaper end so the filters probably aren’t the greatest.

RO/DI Basic Guide

There are always a lot of questions regarding which RO/DI setup do I need, how many stages, how do I know when to change filters/membranes, I’m getting a weird TDS value, etc. Hopefully this clarifies a few things and helps some of you out one day. My first recommendation would be to find the...

www.reef2reef.com

This should help answer and give you some additional background information.

 

[Indiana Jones]

Can you check between stages? Although it will exhaust very fast, brand new DI resin should be putting out 0tds.

Something doesn't sound right here.

How do you recommend checking the stages? Sorry I’m kind of new to all this

 

[Woodyman]

How do you recommend checking the stages? Sorry I’m kind of new to all this

Give the link I posted above a read. I go over all of that in that thread.

 

[Woodyman]

How do you recommend checking the stages? Sorry I’m kind of new to all this

If you've got it installed correctly the resin is bad.

Did you get a reading before you ran 60 gallons? Did it read 0 TDS at any point?

 

[Indiana Jones]

If you've got it installed correctly the resin is bad.

Did you get a reading before you ran 60 gallons? Did it read 0 TDS at any point?

Im not sure. I didnt have a TDS meter until today. Is there any specific resin you recommend? I think this unit can take any 10" filter

 

[Indiana Jones]

Give the link I posted above a read. I go over all of that in that thread.

Thank you! im reading now

 

[Woodyman]

Im not sure. I didnt have a TDS meter until today. Is there any specific resin you recommend? I think this unit can take any 10" filter

Plenty of people use and are happy with BRS.

Personally I use the Spectrapure resins, but you don't have to. They are typically more expensive, my experience says they last longer, but my water isn't the same as yours or someone else's.

I don't remember what brand @Opus uses.
I think @KStatefan uses Spectrapure as well.

Anything other than the bargain basement Amazon resin will probably suffice. Being new I'd recommend just buying it pre-packed. Get comfortable with your system before you try packing it yourself if you want to go that route.

If it's installed correctly you should get a reading of 0 TDS out of your DI.

Have you checked the TDS out of the membrane to determine a rejection%?

 

[Indiana Jones]

Plenty of people use and are happy with BRS.

Personally I use the Spectrapure resins, but you don't have to. They are typically more expensive, my experience says they last longer, but my water isn't the same as yours or someone else's.

I don't remember what brand @Opus uses.
I think @KStatefan uses Spectrapure as well.

Anything other than the bargain basement Amazon resin will probably suffice. Being new I'd recommend just buying it pre-packed. Get comfortable with your system before you try packing it yourself if you want to go that route.

If it's installed correctly you should get a reading of 0 TDS out of your DI.

Have you checked the TDS out of the membrane to determine a rejection%?

I'm not sure if this is what you mean, but I just checked the TDS out of the "filtered" part and it was 11 ppm. Straight out of the tap its about 280 ppm now. So the rejection would be 96%?

 

[Woodyman]

I'm not sure if this is what you mean, but I just checked the TDS out of the "filtered" part and it was 11 ppm. Straight out of the tap its about 280 ppm now. So the rejection would be 96%?

On the lower end, it may go up as it breaks in further since it's still new.

I don't know what the Aquatic Life membrane is, whether it's a Dow or something else I don't know. Typically new membranes will give you 98%+ but anything above 96% is ok.

I use the 99% tested spectrapure's listed below which are rebranded Dow's.