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RO Water Nano Tank Mix Quantities

SilverBee

Seedling
Joined
20 Apr 2021
Messages
6
Location
London
Hi All
I'm new to the forum and really excited to have joined! I'm a beginner (this is my second set up and my first was a bit of a catastrophe).
I had some questions regarding water chemistry and RO water. I previously used tap but my source water is extremely hard (London) and is very high in Nitrate as well which contributed to a lot of algae issues in my first set up.

I've recently set up my 20 litre, planted nano tank. I've elected to use 100% RO water which I am remineralsing, and I wanted to ask if others have done this and how they scaled their doses for various quantities of water for a nano tank, i.e. large quantity at start up, 50% water changes and 20% water changes and so on.

I'm using Seachem Replenish, Seachem Acid Buffer and Seachem Alkaline Buffer, with the aim of attaining the following water chemistry: dGH 1 (2.5ml per 20litres), pH 6.5 (Acid Buffer 1.2g per 20litres & Alkaline Buffer (KH for pH stability)1.5g per 20 litres).

In order to scale the doses down, with Acid Buffer as an example for a 50% water change of 10 litres:
1.2g/20litres = 0.06g per litre x 10 = 0.60g

I have observed however that my dGH is sitting between 5.4-6.4 which is much harder than I was aiming for (aiming for 1)

I don't know where I should expect KH to be based on the Buffers (as Seachem aim for pH rather than a KH reading) but it's sitting at around 3 when the water is mixed and drops to 2 in the tank after about a day (though sometimes freshly mixed water is reading as 2). I expect the KH to go down in the tank as I'm also using Tropica soil which has some buffering capability. Is there a converter for KH vs pH? I'm assuming not since the KH is just to stabilise the pH, not create it.

My pH is stable and generally reads at 7 though sometimes it looks a bit more orange than red so I expect its sitting between 6.5 and 7.

Bottom line, is it normal to see some mild fluctuation? I'm also seeing the KH dropping over a number of days. I'm currently in week 3 running 20% water changes twice a week and moving to 20% water changes once a week from next week onwards. Someone suggested that 20% water changes are not enough and I should carry out 50% weekly, but I'm not sure the reasoning for this.

Should I be scaling my quantities the way that I currently am or is there a more accurate way to do this?

And lastly, should I be overly concerned? The tank has been set up for a week and 2 days and I plan to stock 6 Chili Rasbora (though it currently seems better suited for shrimp at the moment!)

If helpful, since set up:
Daily 50% water changes for the first week (no ferts)
Alternate Day 20% water changes for second week (ferts)
Will aim to drop to either weekly 20% water changes or bi-weekly 10% water changes (ferts)
Light is on 6 hours for first 3 weeks, to then increase to 8 hours
Tank is heavily planted with all easy grade plants including; Anubias, Spikey Moss, Bacopa, Crypts and Sagittaria
No CO2 this is a low energy set up with low light as well.
Hardscape: Lava Rock, Wood (not sure which type honestly), sand and Tropica Soil

Cheers in advance!
 
Hello SilverBee, I am a fellow Londoner! And was a newbie last year :) It would be great to see a photo of your tank, that always helps us see if there are any problems or things you haven't picked up on yet.

1. As @ian_m says, high nitrates don't cause algae - indeed plants love a good bit of nitrate. Many of us at UKAPS are dosing extra nitrate to help plant growth, and this doesn't make the algae problems worse, in fact it makes them better because healthy plants = less algae. Algae is caused by broken-down waste chemicals like ammonia. I have a London tapwater nano for my cherry shrimps, and both the shrimps and the plants thrive in it with hardly any algae, many people on UKAPS use London and other hard tap without any problems. Algae outbreaks happen to us all, they just need a bit of management to get under control, so if algae appears, don't panic! It's almost always salvageable.

2. You've done this with your setup, so you know that big waterchanges (50%), and very frequent ones are suggested when you start up your tank to get out any extra bad stuff in the water which can cause algae, as when a tank is new it doesn't have the bacteria, plant mass and ecosystem built up to absorb these waste chemicals in the tank, this takes a good 6 weeks, if not longer to mature enough to support some fish. Generally, there are a lot more waste chemicals in the water when a tank is new, due to the soil.

50% waterchanges are good after you've set up your tank and it's matured though as well, to keep the water clean which is healthier for the animals. Many people here have hightech (CO2) systems which require 50% changes weekly to get rid of the high accumilation of fertiliser and plant emissions. In a lowtech (no CO2) tank it's not a requirement, but it does make algae easier to keep at bay and fish health better, in my lowtechs I do 30-40% weekly, 50% monthly with a filter cleaning and on my nano 23L 50% weekly because A) it's easy and B) nano tanks are very small with a low volume, any animals are going to foul the water quickly. Your idea of 2 smaller waterchanges a week is a good one.

3. Stability comes with time - I wouldn't worry about the fluctuating parameters of the water right now, it's because the tank and everything in it is new. Water properties can and will change throughout the week, depending on your substrate, your hardscape, the time of day, the temperature, amounts of O2 and CO2 from plants, etc. Stability will come with time, as the tank matures, as time goes on it will only get more stable, and you will be more confident in your fishkeeping and know you don't need to worry about it fluctuating a bit.

4. Cheaper is often better, and easier. You could almost certainly just remineralise your RO with a % of tap water instead of the various buffering chemicals. I would try adding 10% incriments until the values seem right, and maybe up to 30-40% to make your life easier in the longrun. Other users know a lot more about this though!

5. Living in London, it's best to match up the water to the fish - use tap for an easier life, unless you want to keep softwater creatures, then... use RO or rainwater, life is harder but you have extra nice fish. Even though you don't need RO water to have a nice planted nano tank, I don't think you using RO water is a bad thing, because chilli rasboras like quite soft water. All this to say... there's nothing wrong with using tapwater as you originally thought, but also no problem to keep using RO, not for the plants but for the fish. Softwater fish have shorter lives in hardwater, as salts build up in their organs. What fish need most of all is plentiful clean water!
 
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Hi all,
I'm using Seachem Replenish, Seachem Acid Buffer and Seachem Alkaline Buffer, with the aim of attaining the following water chemistry: dGH 1 (2.5ml per 20litres), pH 6.5 (Acid Buffer 1.2g per 20litres & Alkaline Buffer (KH for pH stability)1.5g per 20 litres).
I'd just use a <"small amount of tap water"> to give you some carbonate and general hardness. Because London gets its water from a chalk aquifer all the hardness is derived from calcium carbonate (CaCO3) and that gives you 1:1 dGH/dKH.

I know it doesn't sound <"very scientific">, but you can spend a lot of time chasing "optimal values" that are really just an illusion. Have a look at <"RO Water...... pH ......."> for some more discussion.

Over time we've developed, contrasting, strategies that do away with the need for <"regular water testing">.

I have a real problem with "Seachem", they have an interesting advertising strategy where they are, at best, disingenuous about what <"their products contain, and their function">.

If you want a more measured approach you can make your own <"DIY re-mineralising mix"> from potassium bicarbonate (KHCO3), calcium chloride (CaCl.2H2O) and "Epsom Salts" (MgSO4.7H2O), these are all available cheaply via eBay etc. because of their use in food etc. <"James' Planted Tank"> has details. I think @Zeus. and @Hanuman have added it to the <"IFC calculator as well">.

I have hard tap water and I use rainwater in the tanks, which <"I buffer up a little bit in the winter with tap water"> when the rainwater is softer.

Is there a converter for KH vs pH? I'm assuming not since the KH is just to stabilise the pH, not create it.
There is, but it is a bit of a strange one, because there is a <"very specific relationship between pH and carbonate hardness (dKH)">.

cheers Darrel
 
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I think @Zeus. and @Hanuman have added it to the <"IFC calculator as well">

Yes either from the TargetCalculator or the DIYCalculator, Bespoke remineralisers are straight forward and we have limited clones to copy ATM. We have a new Reminerlising sheet in the developing stage which clones most remineralisers and deals also with Ca:Mg:K ratios as well, it will be some time before its released - however if you was after a clone of something specific just ask
 
Thanks everyone for your replies - I had been meaning to reply much earlier but it's been one of those weeks!

High nitrate does no produce algae. You need to look else where. Many of us dose Estimative Index with what many assume is "high nitrate" and we don't suffer algae.
Thanks for this Ian_m - I always thought the extra Nitrate just fed algae!

Thanks Shangman for the different points of views. I've gone into this project trying to get everything perfect, but I've started to treat it as an exercise in imperfection (I am a perfectionist in need of respecting the weird and wonderful ways Nature likes to do it's own thing). I'm thinking of increasing the sizes of the water changes in time, once I find my rhythm a bit.

3. Stability comes with time - I wouldn't worry about the fluctuating parameters of the water right now, it's because the tank and everything in it is new. Water properties can and will change throughout the week, depending on your substrate, your hardscape, the time of day, the temperature, amounts of O2 and CO2 from plants, etc. Stability will come with time, as the tank matures, as time goes on it will only get more stable, and you will be more confident in your fishkeeping and know you don't need to worry about it fluctuating a bit.
This gave me a lot of reassurance - thank you!

dw1305 Thank you for the comprehensive response and pointing me in the direction of resources - much appreciated. I will take a look into those. I'm slightly apprehensive of mixing my own of anything (be that water minerals or fertilisers) but I may look into those in future!

Thanks to Zeus as well!
 
H all,
I'm slightly apprehensive of mixing my own of anything
You could just add ~10% tap water, that would supply calcium (Ca ++) and carbonate (HCO3-) and you are going to add magnesium (Mg) with your fertiliser addition. I don't actually add a set amount of tap water, I just use a <"conductivity datum range">.
but I may look into those in future!
If you only have low tech small tanks the cost of <"ready made" liquid fertilisers"> isn't too bad, but as the frequency of water changes and water volume increases, so does <"the cost differential">.

cheers Darrel
 
To add my two penneth, I have a 20l shrimp cube (cherries) and use rain water. I draw 5 litres at a time plus a 2 litre bottle, and sling half a spoon of Salty Shrimp in the 5 litre bottle. Most of that does my weekly change, with some of the non-remineralised for top ups if needed. I occasionally check TDS.
Granted if you’re aiming for chillis that’s prob not the right parameters, but just flagging if you’re only running tiny water volumes the off the shelf products really do go a long way.
 
Thanks Shangman for the different points of views. I've gone into this project trying to get everything perfect, but I've started to treat it as an exercise in imperfection (I am a perfectionist in need of respecting the weird and wonderful ways Nature likes to do it's own thing). I'm thinking of increasing the sizes of the water changes in time, once I find my rhythm a bit.

This gave me a lot of reassurance - thank you!
You are definitely on the right path :) I think one of the best things about this hobby is to realise that it is a conversation with nature, we can't control it all, and that is what is great about it! The unexpected ways plants grow and the ecosystem develops is so exciting and satisfying, the aquarium is a collaboration between us, bacteria, fungi, algae, plants and all sorts of animals. Tanks can be perfect, but they take time to develop, it's not immediate, it's a ~journey~ (which sounds like rubbish but I really think is true). You can start with something very basic, and over time you can learn so much, improve it and work on it and turn it into a masterpiece. I do think that the aquarium indulges our perfectionist tendancies, but you don't need to be a perfectionist to get a great tank. Once you have all the basics down, it becomes very holistic where you watch and see and feel to keep the balance.

There are so many styles and ways of approaching things that really it is up to you to define what perfect is in aquaria. For some a hightech super lush tank is perfect, for another it's all about most natural happy behaviour of fish or shrimps, for another it's about emergent growth, for another they want to grow algae on purpose and recreate nature, for another it is something beautiful but very easy to maintain, for another it is a faux tree diorama landscape, it is all about what you want to experiment with and see what you can achieve. You can be very experimental and creative! I think at first, perfection is getting the balance between all of the inputs you do have control over right and understanding how they affect eachother, which is very important! But just remember that it's all about learning and not to put too much pressure on yourself when things go wrong (which they often do lol), whatever happens you will almost always find a post on UKAPS on how to deal with it, and if not there are many experts to advise.

Looking forward to seeing some photos of your tank and how it's developing :))
 
"Perfect is the enemy of good." Voltaire.
WikiP

Remember your goals.
For me;
Healthy plants and livestock.
A tank that is pleasing (to me) to look at.
A tank that doesn't demand more time or money than I can justify spending on it.

Hardness, pH etc are not goals in themselves. And most frshwater plants and livestock are quite adaptable within a range of parameters.
"Give them the third best to go on with; the second best comes too late, the best never comes." Watson-Watt.
 
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