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Help What is best for the freshwater planted tank... RO/DI or just RO?

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I plan to switch from tap water to remineralising my own and I'd like to seek some assistance before purchasing a system.

What is best for the freshwater planted tank? RO/DI or just RO?

At a guess I would have thought RO/DI, but I'm not 100% sure.

Thank you 😊
 
I'd just get a nice RO unit. Whatever you'd have invested into the DI portion, invest into getting a bigger RO unit, or extra prefilter/carbon for replacements.

DI makes the water more pure, but I don't know that it is needed in freshwater. Maybe saltwater? Probably in chemistry labs.

--Steve
 
I'd just get a nice RO unit. Whatever you'd have invested into the DI portion, invest into getting a bigger RO unit, or extra prefilter/carbon for replacements.

DI makes the water more pure, but I don't know that it is needed in freshwater. Maybe saltwater? Probably in chemistry labs.

--Steve
Agreed no need for DI. Pure RO is plenty good for any planted tank.
 
Agreed no need for DI. Pure RO is plenty good for any planted tank.


Thank you Gregg, and @mn_aquascape

I appreciate your responses.

I assume the stored RO water needs to be circulated. What's recommended here, is an air stone sufficient?

Apart from the RO system itself, storage drums and pump to send the water to my tank, is there anything else I need?

Thanks for your help šŸ‘
 
It's nice to heat the water before you use it. You can circulate within your holding barrel/tank with an airstone. Even better to get a decent sized submersible pump to circulate your water, that you can then use to pump water back to your tank. You'll want something that's capable of pushing a lot of water under high head pressure - like what reef keepers might use to return water from a sump. A $30 off brand from Amazon probably won't satsify your needs.

--Steve
 
It's nice to heat the water before you use it. You can circulate within your holding barrel/tank with an airstone. Even better to get a decent sized submersible pump to circulate your water, that you can then use to pump water back to your tank. You'll want something that's capable of pushing a lot of water under high head pressure - like what reef keepers might use to return water from a sump. A $30 off brand from Amazon probably won't satsify your needs.

--Steve

Thank you Steve
 
Hi Joel,

I’m different than others when it comes to this for planted tanks. If you are going to set this up, do it right from the beginning. This will save you from chasing ghosts later on or having to upgrade.

RO will remove between 92-98% of that your water contains. I agree with others that you need to purchase an RO filter that is high capacity and quality. Make sure it’s rated for the gpd that you want and make sure to get a flush valve.

I highly recommend that you get a double carbon block pre filter to deal with chloramines. If you know you don’t have any and won’t in the future, you can get away with one carbon block.

I also always recommend an RODI system. You simply don’t know what is in the 2-8% that the RO filter lets through. Thinks like copper, phosphates, ammonia can make it through an RO filter but are removed by the DI resin. To me, this removes any variables so I’m confident on what my replacement water contains.

If you decide on DI, you can do a single or dual stage. Single is mixed resin and won’t last as long as dual stage that separates the two types of resin. I wasn’t doing too large of water changes so I was able to get away with a single.

Again, setting up this type of system is going to be expensive. I recommend you save up to get the complete package. Can you get away with RO and be fine? Sure. But when you’re spending this kind of money, why take a risk?

#RODI#RODI
 
Thank you Gregg, and @mn_aquascape

I appreciate your responses.

I assume the stored RO water needs to be circulated. What's recommended here, is an air stone sufficient?

Apart from the RO system itself, storage drums and pump to send the water to my tank, is there anything else I need?

Thanks for your help šŸ‘
Hey Joel here's a list things you may need/want depending on your set up.

If you will have two large tanks you would want two Uniseal flexible adapters to tie the two tanks together. The tank you run the water into should have a float valve.

I also use the RO for the home drinking water, so I have a Y splitter on the output that allows for water to run to the large storage tanks and the small RO drinking water storage tank. Then I use a solenoid on a smart strip so that I can control when the unit is sending water to which tanks. It gets a little complicated as you can't really use the home RO at the same time as you are filling the tanks.

In my set up I keep a pump in one of the tanks to pump water up to the tank. But make sure you use a pump that is designed for ponds and is safe for fish and plants. Do NOT use a utility pump!. Those motors are encased in a toxic oil that can wipe out everything that's alive in a tank if they leak. Ask me how I know.

The sizing of the pump is important. Much depends how high you are lifting the water. In my case I am pumping up from a basement to the first floor which is about 15 feet to where it comes out into the tank. So I need a pump with a good amount of head lift. For reference here is the one I use...

Pond Pump

I have an air stone and circulation pumps inside my storage tanks. They are controlled by the smart strip and are both run for four hours twice a day. But honestly just an air stone would probably be just fine too.

I used to run heaters but don't anymore. My tanks are in a basement storage room and the coldest they get is about 60 degrees. Since I run my tank in the low 70's that isn't that much of a differential and the fish and plants don't mind the drop at all (I don't run any heaters in the tank either).

Some options for the RO system which are nice to have are a pressure gauge and an inline TDS meter.

I hope that helps!
 
If you have a reef tank, you want 0 TDS which even with pretty good tap water, you'd need a DI stage.

My TDS out of the faucet is around 112 or so. RO will get me down to anywhere between 3-8 TDS, DI gets me down to zero.

In the grand scheme of things, if you don't already have DI and won't be running a reef tank, it's probably not necessary.
 
Everyone’s situation is different, for myself I would blow through more DI resin than it’s worth. We usually make quite a bit more water than the reef users do, especially with medium to large tanks.

In my situation with a 90gal I’d be looking at monthly DI replacement and isn’t worth the cost. I’ve been there and done that and it’s not required with my source water.

If you do choose to use DI make sure not to run good water through exhausted resin, change it out or remove it all together once it’s used up.
 
Last edited:
If you do choose to use DI make sure not to run good water through exhausted resin, change it out or remove it all together once it’s used up.
This šŸ‘† DI, when exhausted, can release what it took in. You send up with a surge of something that you don't want.
 
This šŸ‘† DI, when exhausted, can release what it took in. You send up with a surge of something that you don't want.
If you have an inline TDS showing pre and post DI, as soon as the post DI reads anything other than 0 TDS it's time to replace the media. If you're going to run DI resin, you almost have to have the inline TDS meter.
 
Hi Joel,

I’m different than others when it comes to this for planted tanks. If you are going to set this up, do it right from the beginning. This will save you from chasing ghosts later on or having to upgrade.

RO will remove between 92-98% of that your water contains. I agree with others that you need to purchase an RO filter that is high capacity and quality. Make sure it’s rated for the gpd that you want and make sure to get a flush valve.

I highly recommend that you get a double carbon block pre filter to deal with chloramines. If you know you don’t have any and won’t in the future, you can get away with one carbon block.

I also always recommend an RODI system. You simply don’t know what is in the 2-8% that the RO filter lets through. Thinks like copper, phosphates, ammonia can make it through an RO filter but are removed by the DI resin. To me, this removes any variables so I’m confident on what my replacement water contains.

If you decide on DI, you can do a single or dual stage. Single is mixed resin and won’t last as long as dual stage that separates the two types of resin. I wasn’t doing too large of water changes so I was able to get away with a single.

Again, setting up this type of system is going to be expensive. I recommend you save up to get the complete package. Can you get away with RO and be fine? Sure. But when you’re spending this kind of money, why take a risk?

#RODI#RODI

Thanks Art,

I ended up going for this system, minus the DI stage. I'll see how I go with it, and if I decide I want to use DI in the future I can easily add to it.


I contacted a few local suppliers and asked a lot of questions. I was particularly happy with the customer service at ReefPureRO, their systems also have good reviews.

Cheers
 
Hey Joel here's a list things you may need/want depending on your set up.

If you will have two large tanks you would want two Uniseal flexible adapters to tie the two tanks together. The tank you run the water into should have a float valve.

I also use the RO for the home drinking water, so I have a Y splitter on the output that allows for water to run to the large storage tanks and the small RO drinking water storage tank. Then I use a solenoid on a smart strip so that I can control when the unit is sending water to which tanks. It gets a little complicated as you can't really use the home RO at the same time as you are filling the tanks.

In my set up I keep a pump in one of the tanks to pump water up to the tank. But make sure you use a pump that is designed for ponds and is safe for fish and plants. Do NOT use a utility pump!. Those motors are encased in a toxic oil that can wipe out everything that's alive in a tank if they leak. Ask me how I know.

The sizing of the pump is important. Much depends how high you are lifting the water. In my case I am pumping up from a basement to the first floor which is about 15 feet to where it comes out into the tank. So I need a pump with a good amount of head lift. For reference here is the one I use...

Pond Pump

I have an air stone and circulation pumps inside my storage tanks. They are controlled by the smart strip and are both run for four hours twice a day. But honestly just an air stone would probably be just fine too.

I used to run heaters but don't anymore. My tanks are in a basement storage room and the coldest they get is about 60 degrees. Since I run my tank in the low 70's that isn't that much of a differential and the fish and plants don't mind the drop at all (I don't run any heaters in the tank either).

Some options for the RO system which are nice to have are a pressure gauge and an inline TDS meter.

I hope that helps!

Hi Gregg,

Thanks for your response here, it's most helpful. I may have another question or two when it comes time to setting everything up, once the system arrives. Hope you don't mind.

If you want to have a look at what I ordered, here it is. They've removed the DI stage as per my request and discounted the system,


I remember reading in another post somewhere about your trouble with the pump and the toxic oil. That would have caused a headache for you I'm sure, hope you had your cold compress handy that day šŸ˜‰

I appreciate you sharing the link for the pond pump. I won't be pumping water as high as you are, but the link gives me some indication of what I'll need. Cheers

I'm really looking forward to setting up the system once it arrives. I haven't decided if I'll get one or two water storage tanks just yet. I did order a float valve.


Thanks again!,
Cheers..
 
Everyone’s situation is different, for myself I would blow through more DI resin than it’s worth. We usually make quite a bit more water than the reef users do, especially with medium to large tanks.

In my situation with a 90gal I’d be looking at monthly DI replacement and isn’t worth the cost. I’ve been there and done that and it’s not required with my source water.

If you do choose to use DI make sure not to run good water through exhausted resin, change it out or remove it all together once it’s used up.

Hi,

Thanks for you comments. My tank is almost 100gal, and I was concerned about having to replace the DI replacement so regularly.

Cheers
 
@Joel Armstrong will this system be auto refilling? If so, I've heard many horror stories with flooding. My suggestion would be to go over your entire design in detail with someone like @GreggZ to make sure you've identified the weak points and have redundancies for critical failures.

What will you store the water in?
 
Hi Art,

No, I am not planning on using the system for auto refilling.

I did think to ask Gregg if/when I have any questions about setting up. He has been quite helpful already, which I greatly appreciate.

I haven't selected anything specific just yet for the purpose of storing the water. One or two reasonably sized water storage drums will be going in my garage.

Cheers,
Joel

😊
 
Thank you Gregg, and @mn_aquascape

I appreciate your responses.

I assume the stored RO water needs to be circulated. What's recommended here, is an air stone sufficient?

Apart from the RO system itself, storage drums and pump to send the water to my tank, is there anything else I need?

Thanks for your help šŸ‘
Here is what I did on my RO storage tank.

There’s a submersible pump inside that feeds up to the vertical PVC pipe on the left of the photo. I split the return line in two and added valves to each. The pipe that goes back to the center of the storage tank has a 45 degree elbow on it, so the water pushes into a sort of whirlpool inside the tank. This pushes anything that might settle back to the center, where it’s picked up by the pump and pushed through again. When it’s time to change the water, I reverse the valves. The vertical portion after the T-union is corrected to a hose, then to a ā€œhookā€ that hangs on the side of the tank.

RO tank.webpTwo-way valves.webpAdjustable Pump.webp
 
Here is what I did on my RO storage tank.

There’s a submersible pump inside that feeds up to the vertical PVC pipe on the left of the photo. I split the return line in two and added valves to each. The pipe that goes back to the center of the storage tank has a 45 degree elbow on it, so the water pushes into a sort of whirlpool inside the tank. This pushes anything that might settle back to the center, where it’s picked up by the pump and pushed through again. When it’s time to change the water, I reverse the valves. The vertical portion after the T-union is corrected to a hose, then to a ā€œhookā€ that hangs on the side of the tank.

View attachment 1491View attachment 1490View attachment 1489
I love it........we might need a thread just for RO system pics!

RO Phase 2.webpRO Tanks.webp
 
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