# R.O Water on big tanks



## Glen Adams (7 Jan 2022)

hey guys

ok so i'm looking into maybe getting a pretty big aquarium (10ft x 2.5ft x 2.5ft) but i'm also exploring about how id use r.o water on it, its probably going to be a monster tank but because the nitrates in my tape water are around 20-30ish ppm amd its generally very hard water, that's gonna be hard to keep them nitrates down with some meat eating fish.... i know that the only way is to buy my on system but how do i store that amount of water? should i buy a high flow (400gpd) system and fill the tank (slowly) during the day adding the mineral and trace elements as it fills?

i'm also interested in what nitrates some of you guys are getting out your tap water?


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## jaypeecee (7 Jan 2022)

Hi @Glen Adams 

I would suggest that you don't need to be concerned about the 20 - 30 ppm nitrate figure of your tap water. But, in my opinion, you might be wise to keep an eye on this over time. A word of warning - avoid the API Nitrate Test Kit. I place my trust in the JBL range of test kits but some aquarists prefer not to use test kits. What is your water hardness? You will be able to get these figures from your water company. Or you could use the API KH/GH test kit. Dependent on the fish you choose, water hardness is where I'd be focussing my attention. I'd be tempted to opt for hardwater fish as this would be a better 'match' to your tap water. Which fish species do you have in mind?

JPC


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## Geoffrey Rea (7 Jan 2022)

Glen Adams said:


> so i'm looking into maybe getting a pretty big aquarium (10ft x 2.5ft x 2.5ft)



You’re not kidding 😂 That is 1769.8 litres of water before in-tank displacement, minus filter capacity, or additional volume of a sump.

Is rain water collection also an option? Is tap water really not an option given the volume?



Glen Adams said:


> i know that the only way is to buy my on system but how do i store that amount of water?



Obviously depends on what it is you’re doing with the tank. However, at those volumes and if you want it to hand you’re in IBC tank territory for storage.



Glen Adams said:


> fill the tank (slowly) during the day adding the mineral and trace elements as it fills?



You would need to sleep before it filled. Even the more rapid RO systems only produce 50-60 litres an hour.

Here’s a video of a 6ft x 2ft x 2.5ft setup that uses continual water change by having the system plumbed:




Unless you have your mind set would seriously consider tap water then design the setup around that. Nitrates are not a problem in a planted tank, if that’s the intention.


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## jaypeecee (7 Jan 2022)

Hi again, @Glen Adams 

You could consider a company called _Spotless Water_. But, please do a bit of 'research' with fishkeepers to confirm that their water is OK for fishkeeping. There may be members here on UKAPS that use this company. Anyway, here's a link:

Spotless Water Home

If it's OK, it may be easier than installing an RO unit at home and it will be a good deal cheaper than getting RO water from _Maidenhead Aquatics_, for example.

Good luck!

JPC


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## jaypeecee (7 Jan 2022)

Hi yet again, @Glen Adams 

I agree with the points made by @Geoffrey Rea. Out of interest, I assume you must have a floor that can support the weight of your proposed new tank? 

JPC


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## Maf 2500 (8 Jan 2022)

I agree we need to know what fish and plants are likely to be introduced before we can rule out the tap water purely on the grounds of nitrates.

A copy of the water report from the local water company would answer a lot of questions.

@jaypeecee I like the idea of Spotless Water and wish they had an outlet near me. However the OP is probably going to need 500kg+ of water per week so it is not going to be very practical to transport by vehicle.


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## sparkyweasel (8 Jan 2022)

Hi @Glen Adams I suggest you don't believe all you've been told about nitrate and hardness. A lot of 'information' out there is just wrong.
If you fancy using the search box you can find a lot if good info on here, much of it is backed up by links to modern scientific research. And it comes from people who are not trying to sell you anything.
You will find lots of us are quite happy with 30ppm nitrate from the tap, and many don't worry about hardness. The hardness depends on your choice of fish, but most are happy in a range of hardness, what species are you planning?
For nitrate info you could start here;
Nitrate toxicity


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## Conort2 (8 Jan 2022)

As mentioned by others we need to know what species of fish you plan to keep. There’s a good chance you may not need to worry about RO.

 I dread to think how long it would take to fill a tank that size with RO!

Cheers


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## AlecF (8 Jan 2022)

As a side road, what's the issue with API testing kits? (he says eyeing his up).


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## Wookii (8 Jan 2022)

As others have said, a 1,700 litre tank is a beast - you need to do a lot of planning ahead to design the system or you’ll be spending every waking hour maintaining it.

Again as mentioned above, you would be wise to try and design the tank (including selection of its inhabitants) around your tap water - but I know that can be difficult if you have your mind set on certain fish.

Although 1,700 litres is an awful lot of water, it’s not unmanageable even with RO, once it’s filled, if you are prepared to invest in automating the system. 

For example you could get a 50 litre container which should fit easily under your tank, and have the RO unit (including the flushing line) on electronic ball valves, timers and float valves, such that the container auto-fills 3-4 times a day. 

If you fit the tank with a decent overflow system connected to mains waste or the garden, then you can simply pump the RO water up to the tank 4 times a day and old water will flow out. That gives you a 10%+ daily water change or there abouts.

A good quality double membrane RO unit should be able to produce 50 litres within a couple of hours, so you would not be limited on when or how many of those water changes you do.

A good quality auto-dosing system (e.g. EcoTech Versa, GDL etc) will handle any and all dosing of both remineralisers and ferts as needed (in terms of quantity, frequency and speed of dosing) to support the water changes.

I assume with a system this large you are going to be going with a sump, which although adds a complete additional layer of complexity, does allow for other maintenance time saving such as fleece roller pre-filters and the like. It might mean you need to think of other solutions for changing the water (as a ‘fill and overflow’ water change system won’t work well with a sump) such as auto-water change units like the Kamoer X2SR Pro.


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## Zeus. (8 Jan 2022)

As others have said that a lot of water to put through an RO unit and if your water is very hard to start off it will take even more water to process the water, your water bill will shoot through the roof unless your on a bore hole with your own water supply. 
Google your water company and get a water report and post it so we can see how hard it is


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## PARAGUAY (8 Jan 2022)

Its going to be great to see this tank🙂


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## Glen Adams (8 Jan 2022)

jaypeecee said:


> Hi @Glen Adams
> 
> I would suggest that you don't need to be concerned about the 20 - 30 ppm nitrate figure of your tap water. But, in my opinion, you might be wise to keep an eye on this over time. A word of warning - avoid the API Nitrate Test Kit. I place my trust in the JBL range of test kits but some aquarists prefer not to use test kits. What is your water hardness? You will be able to get these figures from your water company. Or you could use the API KH/GH test kit. Dependent on the fish you choose, water hardness is where I'd be focussing my attention. I'd be tempted to opt for hardwater fish as this would be a better 'match' to your tap water. Which fish species do you have in mind?
> 
> JPC


To be fair i did test with the API test kit... are these known the be inaccurate? I do also have the Nutrafin Master Test Kit and ill test the water again at some point.

Species that im considering - a fairly high grade arowana (high back red tail golden), a couple of peacock bass, datnoid, large clown loach (which i already have)... debating about oscars but think they could be trouble? 
​


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## Glen Adams (8 Jan 2022)

Geoffrey Rea said:


> You’re not kidding 😂 That is 1769.8 litres of water before in-tank displacement, minus filter capacity, or additional volume of a sump.
> 
> Is rain water collection also an option? Is tap water really not an option given the volume?
> 
> ...



ive definitely thought about rainwater but my local aquatics warned me off due to contaminates... im currently experimenting with pothos (devils ivy) to see if that reduces the nitrate... maybe a sump with a section of plants could be a way forward?


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## Glen Adams (8 Jan 2022)

jaypeecee said:


> Hi yet again, @Glen Adams
> 
> I agree with the points made by @Geoffrey Rea. Out of interest, I assume you must have a floor that can support the weight of your proposed new tank?
> 
> JPC


yeah its ground floor on concrete, we're all good there lol


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## Glen Adams (8 Jan 2022)

Maf 2500 said:


> I agree we need to know what fish and plants are likely to be introduced before we can rule out the tap water purely on the grounds of nitrates.
> 
> A copy of the water report from the local water company would answer a lot of questions.
> 
> @jaypeecee I like the idea of Spotless Water and wish they had an outlet near me. However the OP is probably going to need 500kg+ of water per week so it is not going to be very practical to transport by vehicle.


Species that im considering - a fairly high grade arowana (high back red tail golden), a couple of peacock bass, datnoid, large clown loach (which i already have)... debating about oscars but think they could be trouble?


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## Conort2 (8 Jan 2022)

Glen Adams said:


> Species that im considering - a fairly high grade arowana (high back red tail golden), a couple of peacock bass, datnoid, large clown loach (which i already have)... debating about oscars but think they could be trouble?


I think you’d be ok with tap. Do you know what the taps like where you’re from? 

Can understand why you’d want to have full control over your water though, high grade Asian arowana are not cheap.


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## Glen Adams (8 Jan 2022)

sparkyweasel said:


> Hi @Glen Adams I suggest you don't believe all you've been told about nitrate and hardness. A lot of 'information' out there is just wrong.
> If you fancy using the search box you can find a lot if good info on here, much of it is backed up by links to modern scientific research. And it comes from people who are not trying to sell you anything.
> You will find lots of us are quite happy with 30ppm nitrate from the tap, and many don't worry about hardness. The hardness depends on your choice of fish, but most are happy in a range of hardness, what species are you planning?
> For nitrate info you could start here;
> Nitrate toxicity


i think the reason why i wanted to go down the ro route was because of wanting to purchase a fairly high grade arowana..

Species that im considering - a fairly high grade arowana (high back red tail golden), a couple of peacock bass, datnoid, large clown loach (which i already have)... debating about oscars but think they could be trouble?


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## Glen Adams (8 Jan 2022)

Conort2 said:


> As mentioned by others we need to know what species of fish you plan to keep. There’s a good chance you may not need to worry about RO.
> 
> I dread to think how long it would take to fill a tank that size with RO!
> 
> Cheers


Species that im considering - a fairly high grade arowana (high back red tail golden), a couple of peacock bass, datnoid, large clown loach (which i already have)... debating about oscars but think they could be trouble?


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## Glen Adams (8 Jan 2022)

Zeus. said:


> As others have said that a lot of water to put through an RO unit and if your water is very hard to start off it will take even more water to process the water, your water bill will shoot through the roof unless your on a bore hole with your own water supply.
> Google your water company and get a water report and post it so we can see how hard it is


this is exactly what i was thinking... the waste would be high, southern water price per cubic metre is around £1.48

one cubic metre = 1,000 litres

if the r.o unit waste was double that of purified water then roughly each water change would cost me no more £4.44.. (£230.88 per year)

i could be wrong tho.. but if you compare how much it could cost to get ro from an aquatics, its not too bad


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## Glen Adams (8 Jan 2022)

PARAGUAY said:


> Its going to be great to see this tank🙂


its not definite yet..  just exploring and looking into it lol


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## Glen Adams (8 Jan 2022)

Conort2 said:


> I think you’d be ok with tap. Do you know what the taps like where you’re from?
> 
> Can understand why you’d want to have full control over your water though, high grade Asian arowana are not cheap.


i did try and look last night but couldn't find the info on it, i'm on southern water in the Southampton area.. i know that the water isn't great cause multiple fish shops have also spoke of this


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## kammaroon (8 Jan 2022)

Glen Adams said:


> southern water in the Southampton area


You can get a report from this link How hard is your water?


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## Glen Adams (8 Jan 2022)

kammaroon said:


> You can get a report from this link How hard is your water?


just as you sent the link i was on there lol 

112.4 ca mg/l - southern water class this as hard


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## Glen Adams (8 Jan 2022)

Conort2 said:


> I think you’d be ok with tap. Do you know what the taps like where you’re from?
> 
> Can understand why you’d want to have full control over your water though, high grade Asian arowana are not cheap.


112.4 ca mg/l - southern water class this as hard


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## Conort2 (8 Jan 2022)

Glen Adams said:


> i know that the water isn't great cause multiple fish shops have also spoke of this


I haven’t got a clue about Asian arowana but I know of a few people that keep them in London tap water which I’m sure must be worse than southampton? Like wise I know of someone who keeps big cichla in tap water and they seem to do great. 

If you can get an automated system going it will certainly be less of a chore.


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## Parablennius (8 Jan 2022)

A word of caution here if I may? If you end up buying RO from a LFS don't assume that that's what you get. A mate down home counties way had all kinds of problems. I told him to get a TDS pen, his alleged RO read 120ppm! Then he was adding minerals on top. Double what my tap reads. He now gets his from Spotless Water


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## Glen Adams (8 Jan 2022)

yeah he shouldn't be getting those sort of readings from their r.o unit. i would do plenty of research first before purchasing

I've just created an account for spotless water, I think it would be good for my smaller tanks but I have one question, is there a way of them delivering it? me myself transporting 600l a week isn't really ideal


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## Zeus. (8 Jan 2022)

The percentage of RO water produced can be as little as 5-15% of water used, so your running cost of water alone could exceed £1000


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## sparkyweasel (8 Jan 2022)

Glen Adams said:


> Species that im considering - a fairly high grade arowana (high back red tail golden), a couple of peacock bass, datnoid, large clown loach (which i already have)... debating about oscars but think they could be trouble?


Is that an Asian Arowana? I don't know about those; a friend raised some _Osteoglossum bicirrhosum _in our hard tapwater from babies to three feet long.
I've had Clown Loach grow from an inch to over a foot in tapwater. 
Another friend had various _Datnioides _spp, he used tapwater, but some species needed salt added for brackish water, so you might need to check which ones. They can be quite shy, may not be ideal with boisterous fish although in your tank size it may not be a problem, with plenty of space for all.
Oscars are _usually _trouble.  Again, a big tank could lessen the problems. I will only introduce Oscars to tankmates when I have enough tanks to be able to separate them again if necessary. The same with introducing a male and a female together. They will be fine in tapwater though.


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## sparkyweasel (8 Jan 2022)

Glen Adams said:


> i did try and look last night but couldn't find the info on it, i'm on southern water in the Southampton area.. i know that the water isn't great cause multiple fish shops have also spoke of this


I've never known a shop say that you don't need to buy the stuff they sell to fix problems that may not exist.


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## jaypeecee (8 Jan 2022)

AlecF said:


> As a side road, what's the issue with API testing kits? (he says eyeing his up).


Hi @AlecF 

Not all API Test Kits are unreliable. But, over the last few years, people have found the API nitrate test kit to be unreliable. One of the reagents needed a _lot_ of shaking to mix the sediment that formed in the reagent bottle. And even then, it wasn't trustworthy. Unfortunately, I cannot remember which of the reagents was a problem. But, I recently noticed on a well-respected aquatics forum that this continues to be a problem for a few people.

JPC


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## jaypeecee (8 Jan 2022)

Parablennius said:


> A word of caution here if I may? If you end up buying RO from a LFS don't assume that that's what you get. A mate down home counties way had all kinds of problems. I told him to get a TDS pen, his alleged RO read 120ppm!


Hi @Parablennius 

This has happened to me several times. On one occasion, the RO water had been accidentally mixed with the feed to the marine tanks! Since that time, I always take my conductivity meter along with me whenever I buy RO water. Some aquatics stores don't even have their own hand-held conductivity/TDS meter. Nor do they have a meter monitoring the output from the RO membrane and DI cartridge. It's always worth confirming exactly what an LFS is providing. In order to get the purest water from your LFS, it is necessary to use both an RO membrane and DI cartridge. That's because RO membranes don't remove ionics and that's where the DI cartridge comes in.

JPC


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## Glen Adams (9 Jan 2022)

sparkyweasel said:


> Is that an Asian Arowana? I don't know about those; a friend raised some _Osteoglossum bicirrhosum _in our hard tapwater from babies to three feet long.
> I've had Clown Loach grow from an inch to over a foot in tapwater.
> Another friend had various _Datnioides _spp, he used tapwater, but some species needed salt added for brackish water, so you might need to check which ones. They can be quite shy, may not be ideal with boisterous fish although in your tank size it may not be a problem, with plenty of space for all.
> Oscars are _usually _trouble.  Again, a big tank could lessen the problems. I will only introduce Oscars to tankmates when I have enough tanks to be able to separate them again if necessary. The same with introducing a male and a female together. They will be fine in tapwater though.


yeah Asian Arowana... im kind of doing my research, seeing how much everything is going to cost etc etc.. ive recently brought my own place so now i can have what i want lol and no girlfriend to say no so i have all sorts of things going through my mind! the idea was maybe have the big monster tank in the dining room, but i do also like the whole planted tank too so im thinking a nice 4ft in the living room for a high tech planted tank

currently have a 600l (rena 600) with 6 clown loaches, red spotted cichlid, 2 bristlenose pleco, dwarf gourami


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## MichaelJ (9 Jan 2022)

Glen Adams said:


> hey guys
> 
> ok so i'm looking into maybe getting a pretty big aquarium (10ft x 2.5ft x 2.5ft) but i'm also exploring about how id use r.o water on it, its probably going to be a monster tank but because the nitrates in my tape water are around 20-30ish ppm amd its generally very hard water, that's gonna be hard to keep them nitrates down with some meat eating fish.... i know that the only way is to buy my on system but how do i store that amount of water? should i buy a high flow (400gpd) system and fill the tank (slowly) during the day adding the mineral and trace elements as it fills?
> 
> i'm also interested in what nitrates some of you guys are getting out your tap water?


If the fish your getting are breed in captivity I wouldn't worry about the tap nitrate levels being in the 30ppm range and hard water (112 mg/l Ca is 15.7 GH ... NOT counting for Mg contents, which is likely low in your neck of the woods. Hard, but not exceptionally...).  High nitrate levels that does not originate from organic waste production is not a problem.... Arowana are huge, hardy and very messy fish - what you do want to pay attention to though is waste buildup as these beasts will generate a lot of waste, so massive regular water changes (using dechlorinated tap water) will be mandatory and with a tank this size it better not be a hassle.  Make sure your source for these expensive fish raised them in water that are reasonably within the range of your tap water otherwise you may have to acclimate them.

Cheers,
Michael


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## mort (9 Jan 2022)

I agree that if you make waterchanges the least hassle they can be then you will more likely keep up with them. Fish can also be very adaptable, especially if you aren't trying to breed them. A friend has a 11x5x5ft tank that was originally marine but he didn't want the hassle so went tropical instead and kept peacock bass, Oscars and some others in very hard local tapwater. It's in the midst of becoming a massive riparium.
My clown loaches and south american fish have been living happily in very hard tap water and there is nothing in there bought this century, the clowns are from 1992 and the others mid 90's.


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## fredi (10 Jan 2022)

Years ago when i started keeping Tropheus, i was struggling to get nitrates to a suitable level (for tropheus, in heavily stocked tank), i found that my tapwater was 30-40ppm
I used ion exchange resin, in a column, to remove nitrates from tapwater, result zero nitrates in tapwater and controllable nitrates in tank water


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## robinj (10 Jan 2022)

Glen Adams said:


> this is exactly what i was thinking... the waste would be high, southern water price per cubic metre is around £1.48


Is that the final price? I pay double of that, not in the UK though, but it includes a price for wastewater. I looked on the Southern Water website and  £1.48 is only for freshwater delivery but another  £2.045 for wastewater. Am I right?


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## arcturus (10 Jan 2022)

Parablennius said:


> A word of caution here if I may? If you end up buying RO from a LFS don't assume that that's what you get. A mate down home counties way had all kinds of problems. I told him to get a TDS pen, his alleged RO read 120ppm! Then he was adding minerals on top. Double what my tap reads. He now gets his from Spotless Water


Exactly. You should get the RO equipment from a specialized water filtering store, not from the LFS. And if you are really considering RO to filter such amounts of water, you should look at industrial solutions because the pump and membranes of quality domestic RO units are not designed for such task.


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## dw1305 (10 Jan 2022)

Hi all,


fredi said:


> Years ago when i started keeping Tropheus, i was struggling to get nitrates to a suitable level (for tropheus, in heavily stocked tank), i found that my tapwater was 30-40ppm
> I used ion exchange resin, in a column, to remove nitrates from tapwater, result zero nitrates in tapwater and controllable nitrates in tank water


I'm going to tell you plants are the answer.

I understand it is difficult with herbivorous fish, like _Tropheus, _but that is the great advantage of plants, they are very efficient at depleting fixed nitrogen, and you get a <"visible indication of nutrient content">.  When you harvest the plants that nitrogen (and <"all the other nutrients">) are removed.

Planted tank keepers have to continually add nitrate, mainly due to their relatively light stocking densities and heavy planting, but in <"aquaponic systems plants will still deplete nitrogen levels">.  Most fish-keeping literature and forums vastly underestimate the nitrogen removal potential of plants, particularly floating or emergent ones.

<"Anion selective resins work">, but you have to keep on testing for nitrate (NO3-), to tell when the resin is exhausted, <"which isn't entirely straightforward"> and <"there is the cost issue"> when you treat a large volume of water which has relatively high NO3- levels.

cheers Darrel


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## jaypeecee (10 Jan 2022)

dw1305 said:


> Most fish-keeping literature and forums vastly underestimate the nitrogen removal potential of plants....


Hi @dw1305 and Everyone,

With my latest tank, I can vouch for the above. More details to follow at a later date. I have limited my comment here to submerged plants because those are the only plants with which I have a reasonable amount of experience.

JPC


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## fredi (10 Jan 2022)

dw1305 said:


> Hi all,
> 
> I'm going to tell you plants are the answer.
> 
> ...


Thank you
Yes 
100% agree, i no longer use the resin, stocking levels are now reduced (by the use of Cyprichromis as dither fish, and slightly different layouts), and hence NO3 produced by filters is manageable 
Recharging resin is pretty easy, once a setup is sorted, i used to pump saline solution (made from ro water, as calcium is not good for the resin i was using),through the column, then rinse with ro water, this was done as soon as tapwater was indicated to have 10ppm nitrate 

I do keep various cryptocoryne’s in my tanks (i purchase “new” types from time to time, to try them out), this was initially done for decorative purposes, a side effect is that the fish breed more regularly, the females seem most eager to deposit the fry amongst  the denser plants
I am sure that fast growing plants would be of benefit, i very much doubt that these would last long though, the “trick” ( if there is one), seems to be finding plants that the fish find unpalatable, they will still occasionally tear leaves up though, i think that stem plants would be murdered in short order


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