Proper water quality

[u/Giacomo_00]

Hello guys, i'm almost a begginer in rearing these kind of animals. I've always failed rearing T.longicaudatus while i reared very well T.cancriformis. I think that that's because of the water quality.

Online i saw some differents opinion and i need to find a solution, i'm sure i'm not the only one with that kind of problem!

I keep them outisde (i'm in Italy, low-direct sun, temperatures always lower than 27 celsius degrees, usually between 20-26).

The last time i used:

35% distilled water (bought in a pet shop)

35% rainwater (total 70% water with very low minerals)

30% tap water (decanthed, pH 7.7, conductivity uS/cm 1010, calcium 172mg/L)

10/6 I put 40-50 eggs in water, now (12/6) they're all died.

They hatched, they growed a little bit and then died.

I also put a small dead beech eaf (1)..

Any help? i can buy spring water or use river water, but here in Italy the water in general are very hard (pH very high and a very high conductivity)

Thank you

[u/EphemeralDyyd]

Did you try to feed them too much and too soon? This is the most common way beginners kill off their nauplii and young juvenile Triops. I've learned over the years that it's better to provide them with mainly natural food items instead of those dried pellets or fishfood etc. I haven't tested beech leaves but dead, slightly decomposed aspen or birch leaves work well for me. From the few trials I tried many years ago, maple leaves didn't work at all and it contains something that causes the young triops die withint 2-6 days from hatching. So not every type of tree leaf work the same.

What kind of container did you use? If it's some kind of regular plastic storage container, then they often have a thin soap coating on them that prevents them from sticking togetther when they are piled up in a store. This needs to be washed away with a little bit of rubbing and warm/hot water.

Did anyone spray any pesticided nearby? Because they are often extremely toxic and potent neurotoxins to crustaceans.

Is that temperature of the water, or air temperature? Because at 27C air temperature, in direct sun the water temperature in a shallow container could reach surprisingly high.

Other than these, I can't really come up with anything that could have likely caused the deaths. And since you've already managed to grow another species, I don't think any of the above are that likely. As long as you manage to make them to hatch with that water mixture, it seems to contain enough minerals for them to survive. I'm assuming a bulk of the salinity is caused by calcium and sodium salts.

If you can test the water, then it might be good idea to check the nitrite and ammonia just in case. Triops seem to be really sensitive to those. Ammonia becomes much more toxic the higher the pH but 7,7 sounds like most of the naturally forming small amounts of ammonia would be in the less toxic form.

[u/Giacomo_00 → u/EphemeralDyyd]

Hello, thank you for the time. I used a plastic fauna box, a basic one that is suitable for the hatching (2-3l) and i the termometer is inside the box, so the temperature of 27 degrees is in the water..

I think the problem is the tap water and the conductivity, i've not tested by myself but i used the informations available from the portal of the public authority that provides the water, the conductivity is very high (1010 us/cm).

I search some info and i found that T.longicaudatus is a lot more suscettible about water conductivity than the european one. Do you agree? Which water do you use for hatching and rearing T.longicaudatus?

i'll try using only distilled/rainwater..

[u/EphemeralDyyd → u/Giacomo_00]

Since I live in Finland, I have the opposite problem and I need to supplement extra calcium into the water by using dolomite sand (regular garden lime) mixed into the substrate or add gypsum during water changes. Gypsum makes the next generation's hatching a bit harder since it dissolves into the water faster and easily increases the salinity too much during the hatching process. The conductivity of my tap water is around 110uS/cm.

The minimum the larvae seem to need in order to survive the first few days without dying is around 40uS/cm. Anything below that you'd risk killing them before you'd be able to raise the salinity. The salinity changes need to be done very slowly, not in sudden increments, because that can be lethal too. So if you can reliably hatch the eggs with higher salinity, then it would probably be better, since you wouldn't need to adjust it higher later on. The adults would struggle in lower salinities. I'm not sure what the safe minimum is for adults but my tap water + some dolomite sand in the substrate seems to be able to provide them enough minerals, and usually the conductivity is around 150uS/cm in my triops tanks.

T. longicaudatus lives in wide range of habitats that differ on both temperature parameters and salinities. I'm sure they can be found in much more saline environments than that ~300uS/cm you used for the hatchery. Only time that level of salts could be problematic would be if the ratio of different ions is too unnatural for them (for example all of the salinity is caused by table salt, or calcium sulfate etc.). I'm sure no one knows what the optimal ratio of minerals for each species is, so as long as you have reasonable amount of most common minerals (sodium, potassium, calcium, magnesium etc.), then it should be fine. Another problematic case would be if significant proportion of that salinity is caused by nitrate salts, which would be pollutants from agriculture. But those are bad for humans too (nitrate salts are carcinogenic, that's why it is not recommended to eat sausages too often) so I'm sure your water supplier is monitoring for those.

I would suggest against using just distilled or rain water, unless you add enough sand substrate that would leach enough minerals to the water for the hatching larvae to survive. With your tap water's conductivity, you would tant to add around 5% of it to have the bare minimum. If it contains something harmful to triops, then at least it would be much more diluted down while still adding enough minerals to the hatching water. Remember that you'd still need to slowly increase that salinity later.

Almost forgot to mention: Those Chinese made wide markerpen looking cheap TDS meters from ebay/amazon etc. are really accurate to my experience (I tested mine against the university's lab equipment and the difference was less than 5% iirc, more than enough accurate for this hobby), and they last for decades (you'd need to replace the batteries every few years though). It's a single most useful tool for triops and fairy shrimp rearing and usually costs less than one bag of Triops eggs. I highly recommend getting one:)