I don't know if this questions been asked before but I can't find anything using the search function. I'm about a year into keeping Red Cherrys and I still don't know what the optimum water parameters are for breeding. When I first started out I was getting loads of baby shrimp but now it seems that they've slowed right down. I used to use tap water, which is very hard here with a TDS of around 375, so I started using RO water and setting TDS at 250. I've just tested the tank for TDS (290), KH (9), and GH (4). Are these figures any good for the well being of the shrimp? I've noticed the TDS goes up every day by about 5 ppm. It's only a nano tank of around 15 litres.

Thanks in advance,

Sonny

It might be time for complete tank clean. Gravel vac the substrate and rinse out the filter media (in the old tank water).

100% water change. Which means catching and housing the shrimp and plants in a temporary container/s.

This should get your TDS to not go up so fast. All the debris and organics collected in the gravel and filter media is causing the TDS to to up quicker.

I would aim for a TDS of 200 and try to maintain it there. A complete water change will reset certain minerals lost in a closed eco system.

While the tank is empty, you can think about replacing the substrate as well. It's an option worth taking while the tank is empty. Just remember to keep the filter media under water while all this re-work is going on. Keeping it in the same container you have the shrimp is a good place to store the filter media while you are working on rebuilding the tank.

 

That is a small tank so I would guess the tds rise may be down to evaporation, you could just keep a 1L bottle of RO water (TDS 000) next to the tank and do the top up with that which should keep the tds more level as it will dilute it. Evaporation is purely water and everything else (tds) remains in the tank!

The breeding may be down to the tank just being fully stocked (though it is also likely the parameters are an issue) as any environment can only sustain so much/many creatures, how many shrimp do you think you have in this 15L tank?

The best parameters for neocaridina are, PH 6.5-7.5, TDS 150-250, GH 6-8, KH 1-4. Your parameters seem a bit weird so I am guessing you aren't using RO water with shrimp remineraliser? Or you have something raising your KH as 9 is crazy high??? Maybe recheck that one!

If you do reset the tank as per JayC you will need to do a long drip acclimate before putting the shrimp back in to the tank as the water parameters should be so different from the water they are currently in! It may be a good idea to to clean and start again at this point but bear in mind doing such may mean you will lose some shrimp due to the extreme parameter difference. 

I hope you weren't too affected by the recent storm!

Thanks for the replies, I think I'll do a water and substrate change. I reckon there are only about 20 shrimp left in the tank and I'm sure I did a complete water change quite recently, certainly in the last 6 months. I use RO water and add minerals to suit, maybe I've overdone that. The KH is definitely 9, to be honest, I don't even know what that means. I'll give it my best shot and see what happens, everything crossed!

We've had loads of damage up here with the first storm but I was lucky to get off lightly, just some glass and a ridge tile. The second storm didn't hit us as hard as the first.

I don't know what mineraliser you are using but if it isn't a SHRIMP specific then you should probably get some, there are few different ones, but below link to one,

https://www.pro-shrimp.co.uk/shrimp-king/688-shrimp-king-shrimp-mineral-ghkh-200g-4001615061345.html

The ones meant for shrimps specifically are obviously made to create the right balance PH/GH/KH when used in RO water. And do top ups between water changes/maintenance using pure RO water only! 

Good to hear you were one of the less affected by the storms.

Just checked and it's called Shrimp Minerals so it should be ok. I'll see how much I need to add to my RO water to get the required parameters.

Try mixing the new water to TDS 200, or maybe even less if thr tank parameters have gone up a lot!

As for the horrific KH, perhaps photo the tank for us to see or list everything in the tank as I assume something must be raising that?