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What TDS should I aim for?

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I have 2 of these little horned nerites.
My TDS is currently 167 and never goes higher than 220. My tap water has a kh of around 2 and a gh of around 2 also. I use tap water for water changes but do have a lot of seiryu stone which may add to the mineral content slightly (don't know tank kh as don't test) but wouldn't guess too much as TDS is low. I inject co2 which depresses ph to the low 6's during the photoperiod, but rises to above ph7 after the photoperiod.
Whilst both snails are active and seemingly ok, they havnt grown much or developed horns which I'm guessing is down to the struggle of obtaining the necessary elements for shell development. Ramshorns do ok and reproduce, but don't have a nice sheen to their shells.
Nerites can survive in high tech soft water tanks, but don't thrive IMO.
Cheerio,
Ady.
 
Well, I myself still have a problem with snail shell erosion in one single tank. It started maybe more than a year ago. I have hard water, no issues at all in other tanks. In this tank all the Malaysian trumpets and pond snails have died in the last year. There are 5-6 small surviving ramshorn snails a few of them with eroded shells. I can't figure it out. Gh 12, Kh 8, ph 7.4, TDS around 300-ish, weekly large water changes, no dewormers ever added, bought the tank new.
The interesting part is the plants are doing a lot better since that started happening and the substrate is very old plain sand, full of mulm. My guess is it's gone quite acidic for trumpet snails maybe...but the ponds snails are gone too....
Maybe that substrate is acting like a magnet for stuff the snails need....I have no idea actually...
 
Not true...

The fish need Calcium, Magnesium etc for their Osmoregulatory systems to function properly. Calcium especially- this isn't included in EI ferts.

It's very important to remineralise RO water... Ferts alone do not provide the minerals which are vital to the fishes' health.

Some South American species like Discus and Angelfish can get away with being in neat RO, but other species will suffer.

Also without any carbonate in the tank, KH will be zero, which leads to a very unstable environment.

Don't you get mad pH swings, because your KH will be non existent?


Believe many who use R/O do so because they have fairly hard, to rock hard water and are maybe trying to keep soft water species and possibly breed same..
Many of these folks, use their tap water to provide remineralization 60/40 50/50 R/O tap water, for it likely has enough calcium/magnesium for fish plant's.
Fish food's also contain calcium and often enough to provide for the fishes development.
 
Soft water species are capable of utilizing low calcium/magnesium availability in the water. However, being the sceptic I am, one needs to know whether those people's fish lived their full life spans in whatever conditions they were kept in. Very soft water in a fish tank is not as stable as the one fish encounter in the wild. I'd probably only do it for breeding purposes then go back to more stable stats long term in the range the fish can tolerate.
 
Hi all,
Soft water species are capable of utilizing low calcium/magnesium availability in the water. However, being the sceptic I am, one needs to know whether those people's fish lived their full life spans in whatever conditions they were kept in. Very soft water in a fish tank is not as stable as the one fish encounter in the wild.
Depends on the fish, but black-water fish really are different and need to be maintained in very soft, acidic water containing humic compounds.

If you have a look on the <"Parosphromenus Project"> or <Apistogramma Forum"> you can get an idea of the water parameters.

One problem is that these fish come from waters where there are very low bacterial loads, and are very prone to infection in water with higher microbial loads. The relative lack of bacteria is because of the very low nutrient levels, presence of anti-microbial tannic & humic compounds and the acidity of the water.

If they were easy to keep fish like Satanoperca spp., Heckel Discus, Altum Angels, Apistogramma diplotaenia etc. would be much more available.

Have a look at <"Chemical characterization of the rivers in the Rio Negro basin">.

cheers Darrel
 
Depends on the fish, but black-water fish really are different and need to be maintained in very soft, acidic water containing humic compounds

Yes Darrel. However, they still need Ca and Mg even in those soft/acidic conditions. There's no fish alive that doesn't. I presume this is one of the reasons why its hard keeping them in a fish tank.
 
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Yes Darrel. However, they still need Ca and Mg even in those soft/acidic conditions. There's no fish alive that doesn't. I presume this is one of the reasons why its hard keeping them in a fish tank.
I thought they got Ca and Mg from their diet instead
 
not really because they come from waters where these minerals are in short supply, maybe keeping hard water species in soft water would be a big problem and vice versa. I would think the waste products in their water would harm them before they had a Mg or Ca shortage, if they were fed correctly
 
This study is interesting below about C.adolfoi exposed to Ca2+ free water.

The present study analyzes Na+ and K+ disturbances caused by low pH in two catfish species from the Amazon River. Corydoras adolfoi inhabits ion-poor, black-stained, low pH (3.5-4.0) waters, while C. schwartzi is native to ion-rich waters at circumneutral pH. Fish were exposed to pH 3.5 Ca2+-free, and Ca2+-enriched (approximately 500 micromol/l) water to determine the protective effects of calcium. Net Na+ and K+ fluxes were measured in the water collected from the fish experimental chambers. C. adolfoi was unable to control the Na+ efflux at low pH, exhibiting Na+ loss up to -594 +/- 84 nmol g(-1) h(-1) during the first hour. After 3 and 6 h, net Na+ flux increased by 7- and 23-fold, respectively. In C. schwartzi, at pH 3.5, the initial high Na+ loss (-1,063 +/- 73 nmol g(-1) h(-1)) was gradually attenuated. A K+ loss occurred in both species, but remained relatively constant throughout exposure. High [Ca2+] affected ion losses in both species. C. adolfoi had 70% loss attenuation, indicating incapacity to control Na+ efflux. In C. schwartzi, elevated [Ca2+] completely prevented the Na+ losses caused by exposure to low pH. Rather different patterns were seen for K+ fluxes, with C. adolfoi showing no K+ disruption when exposed to low pH/high [Ca2+]. Thus, C. adolfoi loses Na+ during acid exposure, but has the ability to control K+ loss, while C. schwartzi controls diffusive Na+ loss but exhibits a slightly higher K+ loss. Ion balance was influenced by [Ca2+] at low pH in C. schwartzi but not in C. adolfoi.
 
Well, I myself still have a problem with snail shell erosion in one single tank. It started maybe more than a year ago. I have hard water, no issues at all in other tanks. In this tank all the Malaysian trumpets and pond snails have died in the last year. There are 5-6 small surviving ramshorn snails a few of them with eroded shells. I can't figure it out. Gh 12, Kh 8, ph 7.4, TDS around 300-ish, weekly large water changes, no dewormers ever added, bought the tank new.
The interesting part is the plants are doing a lot better since that started happening and the substrate is very old plain sand, full of mulm. My guess is it's gone quite acidic for trumpet snails maybe...but the ponds snails are gone too....
Maybe that substrate is acting like a magnet for stuff the snails need....I have no idea actually...

Took a picture of a snail just now. All info points my snails shouldn't have calcium deficiencies in my hard water. The rest of the survivors are about the same size, some have normal appearing red shell, some white. Anyone venturing a guess why this is happening in a hard water tank? Water is changed at 50% weekly for around a year without a fail. The issue is just in the one tank with the same tap water as in the rest 4 tanks I have.
Snail_zpsjnmbrnsn.jpg


Snails2_zpslztmksjt.jpg


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I use RO water, and I remineralise using JBL Aquadur.

I typically remineralise to a KH of 4. After dosing with EI, TDS ends up in the 300s.

Should my TDS be lower? If so, that would mean using less Aquadur, which has two drawbacks. Lower KH means pH swings are more likely, and more acidic water means my Nerite snails will not be happy.

So, what is the lowest "safe" KH for a Co2 enriched tank, and how do I make sure my Nerites stay happy in soft water...

Sorry for intruding with my snail issue Sacha. I just thought it maybe useful if someone has an idea as it seems it's not all about Kh, TDS, ph, etc..

My guess about the above questions is that Kh value in a CO2 tank won't matter as the CO2 has very little impact on Kh. It only moves the Ph.
As for reconstituting the water, it all depends on what you use to increase the TDS. I'd just use the same remineralisation product and aim at the same TDS for new water without worrying about Kh, Gh and Ph much. Just go by what your snails are telling you :)
Mine did well in TDS of 200, Gh around 6-7 and Kh of 2, stable ph of 7.4 in a low tech non-co2 tank.
The Kh value you need in order to keep the Ph stable would be unique to your own tank setup, type of water used for water changes, amount of bioload added, etc..maybe some trial and error is needed. I don't think there's one formula for all.
 
Hi all,
Yes Darrel. However, they still need Ca and Mg even in those soft/acidic conditions. There's no fish alive that doesn't. I presume this is one of the reasons why its hard keeping them in a fish tank.
No, I'm not arguing that they don't need salts like Ca++, K+, Na+ etc, they do. Also I know that if you want to kill an obligate hard water fish (particularly from Lake Tanganyika) really quickly you can try keeping it in soft water.

I don't much about fish physiology, but if you look at the paper <"Low pH and calcium effects on net Na+ and K+ fluxes in two catfish species from the Amazon River (Corydoras: Callichthyidae)"> it actually talks about the lack of calcium, and other cations, in the waters inhabited by C. aldofoi.
It is reasonable to propose that Ca2+ does not play any special role in blackwater fish acid tolerance since this element is almost unavailable in the ion-poor waters of the Amazon region. This supports the idea that ion regulation in blackwater systems is modulated by different mechanisms, as previously suggested by others (15,16,18,19).
&
The adaptive strategies involved in acid tolerance in the blackwaters are still a topic of discussion. The physiological adjustments that allow fish to inhabit low pH waters with low ion concentrations seem to be their ability to maintain an ionic balance by a combination of adjustments to enhance transport and limit permeability. Most reports seem to emphasize the idea that ion loss control is the key factor for species survival in acid waters, rather than maintenance of the ion uptake rates. Naturally adapted fish from soft ion-poor waters such as the Amazon blackwaters did not show branchial affinity for Ca2+, indicating modulation by other still unknown physiological mechanisms. The investigation of the effect of dissolved organic carbon compounds on ion regulation should be a fruitful field for additional research concerning the natural adaptations of fish to naturally acidic waters.
cheers Darrel
 
Naturally adapted fish from soft ion-poor waters such as the Amazon blackwaters did not show branchial affinity for Ca2+, indicating modulation by other still unknown physiological mechanisms.

So basically it is not known yet how fish from black water environment utilise Ca2+?
Then we can't argue either way.
 
<"Low pH and calcium effects on net Na+ and K+ fluxes in two catfish species from the Amazon River (Corydoras: Callichthyidae)">

It's a really interesting article. Non-black water cory tolerates a rapid Ph drop from 6 to 3.5 better than the black water cory :)

There's another here about cardinal tetras quite capable of adapting to acid water conditions too. It seems some harder water species can adapt to ion poor acidic water. Some "blacker" water species like clown loaches do quite well acclimated to harder water too. I've seen them even in African Cichlid tanks although that maybe an extreme.

http://www.researchgate.net/publica...lrodi_(Schultz)_subjected_to_extremely_low_pH
 
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There is a bit more on the studies on Amazonian fish and ion fluxes

Several studies of ion fluxes between the fishes and their

external media were performed in samples collected from the

Negro River (Gonzalez et al. 1997, 1998, 2002; Wood et al.,
1998; Wilson et al., 1999; Gonzalez & Wilson, 2001) and some
demonstrated that they are more resistant to acidic waters

than those that do not live in black waters (Wilson et al.,
1999; Gonzalez et al. 1997, 2002). However, only two studies
analyzed Ca2+ fluxes in Amazon fishes, and they were
performed with modified well water, which is similar to the

“clear water” (Wilson et al., 1999; Matsuo et al., 2005). In
addition, transfer of tamoatá (Hoplosternum littorale) and
pirarucus (Arapaima gigas) from black water to white water
or vice-versa induced only minor changes on net Na+, K+ and
Cl- fluxes (Baldisserotto et al., 2008), but Ca2+ fluxes were not
studied. In addition, waterborne Ca2+ uptake occurs much
slower than Na+ uptake (Matsuo et al., 2005).


More here:
http://www.scielo.br/pdf/ni/v7n3/aop0209.pdf
 
Took a picture of a snail just now. All info points my snails shouldn't have calcium deficiencies in my hard water. The rest of the survivors are about the same size, some have normal appearing red shell, some white. Anyone venturing a guess why this is happening in a hard water tank? Water is changed at 50% weekly for around a year without a fail. The issue is just in the one tank with the same tap water as in the rest 4 tanks I have.

I don't know anything about snails, but if you've got calcium then I'd guess the issue would be they are missing something else trace wise they need to build their shell - like plants having plenty of one thing but be limited by something else missing. You'd have to read up on what snail need - humans for example need vitamin D along with calcium - in which case light could be your variant. Or it could be whilst hardness effects shell erosion, it's diet that effects growth and the food is different between tanks?
 
Thanks Tam. The food is the same. Staple pellet I use is NLS cichlid pellets between all tanks. I'd have to research what else they could be missing that this tank might not have. I have no idea right now. I suppose it's not an issue as I have plenty of snails. It's just that I want to know what causes it in this particular tank.
 
Hi all,
There is an explanation of why older snail shells whorls erode in this thread <"Nerite Snails in high tech..">. I think for the vast majority of people water with a reasonable amount of carbonate buffering is going to be preferable, and make aquarium management easier etc.
There's another here about cardinal tetras quite capable of adapting to acid water conditions too.
I think you are going about this the wrong way round. The researchers are trying to find the factors within the physiology of Cardinal Tetra (<"Paracheirodon axelrodi">) which allows them to survive in the acidic, mineral poor black-water, they aren't adapting to it, they are adapted for it.

The paper indicates that humic substances (from the leaf litter) are important. There are plenty of <"academic papers"> on this subject and aquarists have also found this, in <"All the leaves are brown"> & <"Skeptical Aquarist - Leaf litter">.

In the Cardinal Tetra paper it says that they have extremely efficient uptake of available cations (Ca++, K+ etc), which may well be why they don't do well in harder water long term (they accumulate high levels of Ca++ etc, which then interferes with kidney function etc).

cheers Darrel
 
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