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Corydoras in hard water...

Hi Mort,

I assume your tap is already fairly soft? Or is it hard like mine? I do like Corydoras Duplicareus which is similar in size to the Panda, but, as Darrel mentioned that would require soft water as it comes for the upper Rio Negro.

How did you source your Panda and Adolfoi?

Cheers,
Fabio
Duplicareus are fine in hard water. I have a group and they're doing great. Granted they haven't spawned yet but by all accounts they spawn ok in hard water, it's adolfoi whose eggs struggle to develop without soft water. I think most cories do well in whatever water you give them provided there are not extremes. You just may have some issues raising the spawn of species like adolfoi.

Cheers
 
Before aquascapers started adding CO2 to tanks everyone would have said that a fall of pH from alkaline (~pH7.8) to acid (below pH7) in an hour will kill all your fish, but this has proved to be untrue. Changes in pH, caused by addition of CO2, are changes in the the amount of TIC, you have more TIC, and a larger proportion of that TIC is carbonic acid (H2CO3), and the pH falls, nothing else has changed.

Hi Darrel,

Thanks very much for the exquisite explanation. I do understand it's a contentious matter, no doubt, like many things in life. However, when somebody tells you that they have to use buffers to avoid swings caused by the chemicals treatments from the water company, it truly seems far fetched because I had never heard this from other shops! Which is why I then decided to turn to you guys for guidance. Thanks again!

I know we are maybe getting slightly off topic, however I've been noticing a huge difference in the way that plants grow in my RO plus GH+ minerals and my other tank which is just tap water. Limnobium reproduces easily, plants are healthy and thriving in the RO tank... while in the tap water tank plants are struggling. I'm sure you probably already know where the issues might be, probably again water chemistry. Would the full water report from Affinity contain some clues regarding possible deficiencies or problems?

Once again your attention is much appreciated.

Cheers,
Fabio
 
If you can do RO then it's good but I often see people advise that tap is so much easier. I have RO because I make my own for my marine tank anyway so it's easy, the waste is collected to water my garden, but it is nice to be able to simply use tap if need be. This winter I'm building some rain water collection for the tropical tank so might probably will stop my transition to tap water (it's something I only decided yesterday as a winter project and would expand what I could keep in the future).

Hi Mort,

I'm doing RO already for a 30 liters shrimp tank. That is doable, but I wouldn't fancy doing that on a 90 liters tank, especially mixing tap and RO, would need loads of space where to mix the water and logistically would be an issue as I cannot produce my own RO and going to the LFS continuously to pick up RO would really spoil the fun of keeping fish.
Good luck with the rain collection! It looks like Darrel is very happy with his. I wouldn't do it where I live because of Heathrow and the vicinity with the Big Smoke which could be a source of undesirable contaminants.

Cheers,
Fabio
 
Duplicareus are fine in hard water. I have a group and they're doing great.

Hello Conort2,

Nice to know! Thanks for sharing that. How long have you had yours for? What size tank do you use for them? I don't think I will want to breed them, however, if it did happen I would find it quite rewarding.

Cheers,
Fabio
 
Hello Conort2,

Nice to know! Thanks for sharing that. How long have you had yours for? What size tank do you use for them? I don't think I will want to breed them, however, if it did happen I would find it quite rewarding.

Cheers,
Fabio
Only had this group for a couple of months now, they're with a group of gold lasers and quite a few other small community fish. To be honest the stock needs thinning out in there, there are too many different species it doesn't look very natural.

They're in a tank that's 30inches long x 20inches wide x 16 inches high. They seem to be doing well, however I only have one definite female so am on the looo out for my wild caughts.

Cheers
 
Only had this group for a couple of months now, they're with a group of gold lasers and quite a few other small community fish. To be honest the stock needs thinning out in there, there are too many different species it doesn't look very natural.

They're in a tank that's 30inches long x 20inches wide x 16 inches high. They seem to be doing well, however I only have one definite female so am on the looo out for my wild caughts.

We always seem to run into those issues. I'm sure you're right, tank however is nice and wide so I'm sure they're happy.

Good luck with finding some nice wild caught females!

Cheers,
Fabio
 
Hi all,
however I've been noticing a huge difference in the way that plants grow in my RO plus GH+ minerals and my other tank which is just tap water. Limnobium reproduces easily, plants are healthy and thriving in the RO tank... while in the tap water tank plants are struggling. I'm sure you probably already know where the issues might be, probably again water chemistry.
I actually use a floating plant (and usually Limnobium) as an indicator of nutrient deficiencies, this is mainly because you can discount CO2 shortage as a cause of any symptoms. I called it this method the <"Duckweed Index">, partially because it was an alternative approach to <"Estimative Index">, using Duckweed (Lemna minor), and also because they were both methods that didn't require the tank owner to carry out any water testing.

I originally used Lemna minor because it was the plant used in <"water quality bio-assay">, but it is always yellow in soft water, even when there are high nutrient levels. Limnobium has the advantage of growing over a large range of water hardness and nutrient levels, all that differs is the size and vigour of the plant.
Would the full water report from Affinity contain some clues regarding possible deficiencies or problems?
It would, but you can already make some informed guesses based on geology.

Your water is hard and the limestone and chalk aquifers in the UK are fairly pure CaCO3, it hasn't undergone <"dolomotization and tends to have low magnesium levels">. Adding magnesium (Mg) is always a good idea. "Epsom Salts" (10% Mg) are an easily obtainable, and cheap, source. Hard water and high levels of calcium effect the uptake of iron, you need to add chelated iron. Have a look at <"Duckweed Index says ....">.

Both magnesium and iron deficiencies cause yellow leaves (chlorosis), but if your new leaves are small and yellow? iron is the answer. Chlorosis in older leaves can be caused by more elements, the two most likely are nitrogen (N) and potassium (K), usually these are in reasonable amounts in SE England, but they may be deficient if your water comes from a very deep limestone aquifer. You can add them both via potassium nitrate (KNO3). After carbon (C) plants need most nitrogen and potassium, which is why <"they can often limit plant growth">.

A final option is the third macro-nutrient phosphorus (P), but it is less likely to be in short supply. Magnesium and/or iron deficiency are the most likely options.

Really healthy Amazon Frogbit looks like @Timon Vogelaar's in this thread <"Do we really need...">.

cheers Darrel
 
slavery of RO for a bigger tank
If you want to reduce total hardness and you have the facility to catch and store rain water you can always pump this to your tank via an inline heater. Living in West Gloucestershire rain fall is pretty good and my wife lets me collect water butts, (I come back from the tip with more stuff than I take) but this is not possible for some people. I do wonder at the things people buy from their lfs. I think that the freshwater hobby read too much marine reef tank info especially about stability of water chemistry.
 
Hi all,
Living in West Gloucestershire rain fall is pretty good and my wife lets me collect water butts
Same for me, I don't live far away and <"I've always used rain-water">, right back into the 1970's.

I ran into to <"Nick Ridout"> recently, and he told me that I was the person that originally told him he could use rain-water in his tanks, although I have no recollection of this.

cheers Darrel
 
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I ran into to <"Nick Ridout"> recently,
Interesting thread. Always delighted with the flow of information on this forum. Also thought about Daphnia but have not got round to doing anything about it yet. I collect from the garage roof and keep leaf liter in the gutter (in reality can't keep it out, a silver birch overhangs the roof.) Can collect 40 gals in a day if Welsh rain comes in. Trying to pluck up courage to move a 100ltre slim line into the Conservatory. Will have to catch the wife in a good mood. Nice pics of your garden.
 
Adding magnesium (Mg) is always a good idea. "Epsom Salts" (10% Mg) are an easily obtainable, and cheap, source. Hard water and high levels of calcium effect the uptake of iron, you need to add chelated iron. Have a look at <"

Hello Darrel,

Apologies for the long pause, I caught a bug that knocked me off the grid for some time..

I found fairly cheap Epsom Salts at Bridgewater Garden Supplies but it's 16% Mg... Could it still do or it's not for our purposes? Here they talk about 4 grams per litre in garden applications..would that be the same for aquaria?

Thanks very much,
Fabio
 

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Both magnesium and iron deficiencies cause yellow leaves (chlorosis), but if your new leaves are small and yellow? iron is the answer. Chlorosis in older leaves can be caused by more elements, the two most likely are nitrogen (N) and potassium (K), usually these are in reasonable amounts in SE England, but they may be deficient if your water comes from a very deep limestone aquifer. You can add them both via potassium nitrate (KNO3). After carbon (C) plants need most nitrogen and potassium, which is why <"they can often limit plant growth">.

Hi Darrel,

I guess a picture says a thousand words..I've got a mix of dwarf water lettuce, amazon frogbit and duckweek I believe, as this was not intentional but arrived together with the water lettuce...

If it is duckweed, it's definitely the most successful plant I'm growing! Just to give you an idea, the last picture shows how much I have to throw away every month to create some space for the other floaters to grow...

Although it's soft water, I don't see any yellowing of those tiny leaves, which is why I'm not sure whether it is duckweed.

The crypts funny enough have started showing holes in them and yellowing (more like whitening) of the leaves. I know the picture is poor but hopefully clear enough to show the problem.

Thanks as usual for your input.

Cheers,
Fabio

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Hi all,
Epsom Salts at Bridgewater Garden Supplies but it's 16% Mg..
It is fine, it won't be 16% magnesium when you use it, it will be 10% Mg, it is just because of the differing <"water of crystallization">.
Here they talk about 4 grams per litre in garden applications..would that be the same for aquaria?
No, but you can use the <"Rotala Butterfly Nutrient Calculator"> to give you an amount to add.

The maths is easy for "Epsom Salts", because they are ~10% Mg. If you have a 100 litre tank and add 5g of "Epsom Salts" gives you 5ppm Mg in the tank water. Five ppm would be fine as an amount to aim for.
Although it's soft water, I don't see any yellowing of those tiny leaves, which is why I'm not sure whether it is duckweed.
Definitely Common Duckweed (Lemna minor). The leaves are actually a bit yellow, when it is really enjoying itself it is a dark green (like the three colours on the right of the Nitrogen LCC below).

olour-shades-developed-by-nitrogen-parameters_W640.jpg
The crypts funny enough have started showing holes in them and yellowing (more like whitening) of the leaves.
That looks like the older leaves are senescing, it may be a light, rather than nutrient, effect. I thin out the floating plants in the winter, because there is a lot less ambient light.
My hard water tank instead is where growth is really less than satisfactory
The new leaves look good on the Frogbit (Limnobium), which makes me think that the older leaves were suffering from iron deficiency.

cheers Darrel
 
It is fine, it won't be 16% magnesium when you use it, it will be 10% Mg, it is just because of the differing <"water of crystallization">.

That's great Darrel,
I'll get it ordered then.


No, but you can use the <"Rotala Butterfly Nutrient Calculator"> to give you an amount to add.

Thanks very much for sharing this very useful tool.


Definitely Common Duckweed (Lemna minor). The leaves are actually a bit yellow, when it is really enjoying itself it is a dark green

That shows my knowledge on Lemna Minor! You mentioned before that this is really a soft water factor, which is why you switched to Limnobium Laevigatum for the Index. So there's really nothing I can do to improve its look, right?


That looks like the older leaves are senescing, it may be a light, rather than nutrient, effect. I thin out the floating plants in the winter, because there is a lot less ambient light.

Point taken! I will definitely do that!


The new leaves look good on the Frogbit (Limnobium), which makes me think that the older leaves were suffering from iron deficiency.

It looks like I should add some chelated iron to the tank... Any recommendations on where to get the right one? Is it dosed dry like the Epsom Salts or in a solution? Shall I use the Rotala Butterfly Nutrient Calculator for dosing it? I thought I had read something about iron and algae in one of your posts but I'm not sure.
Much appreciated!

Cheers,
Fabio
 
Hi all,
So there's really nothing I can do to improve its look, right?
You can pinch off the older leaves from both the Pistia and the Limnobium, once they've started to yellow and senesce they aren't helping the plant.
It looks like I should add some chelated iron to the tank... Any recommendations on where to get the right one? Is it dosed dry like the Epsom Salts or in a solution? Shall I use the Rotala Butterfly Nutrient Calculator for dosing it?
You can dose it dry and use the Rotala Butterfly calculator. I use FeEDTA, but in harder water one of the <"other chelators is better">.
I thought I had read something about iron and algae in one of your posts but I'm not sure.
It is in the <"Rotala rotundifolia growth issue"> thread.
After dosing some additional Iron (only about 2ml/day) my glass became green after 4 days. After 7 days I had to scrape it off as it looked disgusting. Now stopped dosing it again and my glass is clean again.
I think that shows pretty conclusively that your plants are iron (Fe) deficient. All the green algae (those with the same photosynthetic pigments as the mosses, ferns and higher plants) have the same photosynthetic systems and pathways.
Darrel, I don't quite understand why?
The algae was iron limited (in terms of Liebig's law of the minimum), but could show a rapid greening due to the diffusion of Fe ions into every cell. Once you stopped adding the higher dose of iron, Fe ions went out of solution and it became the limiting nutrient again. Your plants will have taken up iron ions during the period when iron was available, but they won't show a rapid response in greening because they can't move iron ions to the yellow, chlorotic leaves, it is only new leaves that will be greener.
One of the advantages of Duckweed (Lemna minor) is that it has relatively few cells and a <"very quick generation time">, which makes it more like a green algae in its response.

cheers Darrel
 
You can pinch off the older leaves from both the Pistia and the Limnobium, once they've started to yellow and senesce they aren't helping the plant.

Hi Darrel,
Sure, I do this regularly, just behind with the maintenance due to the bug and also cause I wanted to show you the state of the plants. Much appreciated.



That's absolutely great! I wouldn't have probably managed to find it again!


One of the advantages of Duckweed (Lemna minor) is that it has relatively few cells and a <"very quick generation time">, which makes it more like a green algae in its response.

So if I understand correctly the point you're making would this be a twofold kind of advantage? Will the Lemna compete with the algae for the iron or will only darken quicker than other plants?
Thanks very much!
Cheers,
Fabio
 
Hi all,
Will the Lemna compete with the algae for the iron or will only darken quicker than other plants?
Both really, it has a fast potential growth rate, it is in bright light and it isn't CO2 limited, all of which means that it will take in nutrients at a fast rate. The distinction between the green algae and plants is really just an arbitrary one, it is better to think of them all <"as plants">, plants are - "the plants you want" and algae - "the plants you don't want".

Lemna will show a quick response to the <"non plant mobile nutrients">, because it has a really quick generation time for producing new leaves, algae will show an even quicker response, because all their cells are in contact with the water, they don't have any internal "plumbing". For the mobile elements it doesn't make much difference, because all plants can move the elements to both new and old leaves. This is why you get a really quick greening response when you add nitrogen (N), potassium (K), magnesium (Mg) etc. and it was the element that was <"limiting plant growth">.

cheers Darrel
 
Hi Darrel,

That is, as usual, a great response and I keep learning a lot from all those links you always kindly provide! Thanks very much!
Cheers,
Fabio
 
Both really, it has a fast potential growth rate, it is in bright light and it isn't CO2 limited, all of which means that it will take in nutrients at a fast rate. The distinction between the green algae and plants is really just an arbitrary one, it is better to think of them all <"as plants">, plants are - "the plants you want" and algae - "the plants you don't want".

Great distinction Darrel, totally agree.

One last question regarding the Epsom Salts. Can I dose it dry straight into the tank which has got snails, shrimp and one Betta Splendens? Or is it better to dilute it in water first?

Cheers,
Fabio
 
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