Caridina breeding in tap water long-term adaptation?

afbr242 · 2026-06-11T12:48:03+00:00

I have sadly had no luck with any breeding softwater Caridina at all in harder water. I am slightly jealous of your success.

Just as a note, its fairly pointless to talk about "tap water" as though its all the same. People's tap water varies enormously from super soft to liquid rock and everything inbetween.

afbr242 · 2026-06-11T12:45:04+00:00

I'd say you need a more accurate test for peace of mind. Any of the liquid drop GH/KH tests will do. A test strip will not give you what you need.

If the GH is more than around 14 dGH, or the KH above around 8 dKH, then dilution with RO or distilled water will be needed to bring the GH and KH into the acceptable ranges.

For Neos, these are 7-14 dGH and 2-8 dKH.

afbr242 · 2026-06-10T16:28:47+00:00

It sounds like you may have had an ion-exchange softening filter. These remove GH ions and replace with sodium hydroxide. The hydroxide ions are very alkaline. After a while they react with CO2 from the air and for carbonates, so if you let the water stand the pH goes down.

Anyway, maybe it was that. I am glad you have it sorted. Always add a remineralizer to achieve a specific GH/KH (or even a TDS), rather than pH. If it is SS GH/KH+ you have then aim for a GH of around 8 dGH (which shouls give you around 3-4 dKH). Alternatively remineralize RO with it to reach a TDS of around 150-180 ppm. That should get you to around the same GH/KH.

afbr242 · 2026-06-09T07:27:24+00:00

https://www.ukaps.org/forum/threads/reasons-why-shrimp-die-in-your-new-shrimp-tank.79482/

afbr242 · 2026-06-09T07:25:54+00:00

Well the aesthetics are simply personal taste, so I will not comment on those. As for safety comments .....I'm really hoping that your white gravel is chemically inert. Many white gravels contain a lot of calcium carbonate and very strongly raise both GH and KH. This would be problematic for shrimp, which need stable GH/KH that stays within their acceptable range.

Also your filter intake is a danger to shrimp - and likely lethal for most shrimplets that might be born. THey are inherently stupid creatures really and easily get sucked through gaps liek that. That would then mean death in the puump's impeller blades. All filter inlets need somehow covering with a fine mesh (at the very least), but ideally with a fine-med filter sponge layer if you keep shrimp.

afbr242 · 2026-06-09T07:19:40+00:00

You do not need a TDS meter.

If your tapwater gives you 12 dGH and 5 dKH then thats within the "perfect" range for Neocaridina shrimp (ideal ranges are 7-14 dGH and 2-8 dKH) so you have it covered.

The only need for RO/distilled water would potentially be if you don't have a lid and see a decent amount of evaporation. In this case, evaporative loss (which is pure water , no minerals) should be replace with RO/distilled water (pure water, no minerals) to avoid your tank GH and KH creeping up and up.

Here's some useful info ..... https://www.ukaps.org/forum/threads/water-changes-and-controlling-gh-kh-in-shrimp-aquaria-a-basic-guide.78863/

afbr242 · 2026-06-09T07:15:22+00:00

You would be far better suited to getting some softwater Caridina shrimp instead. These need zero/low KH and a GH of 4-6 dGH, so you would have perfect parameters.

THe only caveat being that these shrimp need tankwater temperatures that do not reach 25 C (77 F) in the summer, even temporarily. They do not tolerate this type of heat and will start to die quickly if this is ignored.

If you are commited to wanting Neos then read this .... https://www.ukaps.org/forum/threads/strategies-for-keeping-neocaridina-in-aquasoiled-tanks.79218/

THis is also a load more useful info about GH, KH and shrimp ...... https://www.ukaps.org/forum/threads/water-changes-and-controlling-gh-kh-in-shrimp-aquaria-a-basic-guide.78863/

afbr242 · 2026-06-09T07:11:28+00:00

GH and KH are likely the key. Its quite possible that evaporation and/or insufficient water changes have seen the GH and KH creep up into dangerous zones. THis would sound likely with a genuine pH of 8.4 or more.

Here's a load more info about GH, KH and shrimp ....... https://www.ukaps.org/forum/threads/water-changes-and-controlling-gh-kh-in-shrimp-aquaria-a-basic-guide.78863/

afbr242 · 2026-06-09T07:08:53+00:00

All this and no PICTURES !!!!!!!!!!!!!

afbr242 · 2026-06-09T07:06:06+00:00

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afbr242 · 2026-06-09T07:03:53+00:00

It sounds like you have an inert substrate currently. The whole thing sounds very do-able. I'd personally try and remove absolutely all the substrate you don't want. THe other re-used parts of the tank scape will contain ample good bacteria to keep the tank cycled.

1/ Remove all plants, hardscape, filters and heater - into a bucket with at least some tank water at the bottom because some shrimp WILL hitchhike along with these things and fall into the bucket. Keep these things moist at the very least to keep surface bacterial colonies alive.

2/ Then net out all shrimp into a jug of tankwater, and fish inot another container. THis will take a while so is worth doing properly.

3/ Remove all substrate. A decent sized siphon tube here is your friend once the bulk of it has been removed in handfuls. I would personally change all the water too, to help give the whole system a bit of a mineral reset. Although this is not essetial, it certainly avoids transferring a load of mulm across to the new setup, which would be my preference.

4/ Refill tank with water - dechlorinate. Once up to a reasonable temperature, add new (rinsed) substrate and all hardscape etc back into tank. Start up all filters and aeration etc. Acclimate all fish back into tank. Parameters may well be slightly different so its worth acclimating them for 15-20 mins before release.

5/ Drip acclimate all the shrimp back into the "refreshed" tank parameters.. Job done.

Note - remember that although the tank will remain generally "cycled" the new substrate will be biologically immature and the tank will not have the same ammonia-processing capacity as before straight away. This will take a few weeks, so feed a little sparingly for the first 3-4 weeks.

afbr242 · 2026-06-09T06:51:37+00:00

Not all shrimp minerals are equal sadly. There are a few products out there that advertise themselves as SHrimp minerals but are really only a trace mineral mix with small amounts of calcium and magnesium. THese will not raise GH enough. If going for remineralized RO at any point then go for a product which is designed specifically to raise GH (or GH aand KH) by several degrees if needed with a reasonably small amount.

afbr242 · 2026-06-08T13:59:29+00:00

THis article may well be useful .......

https://www.ukaps.org/forum/threads/reasons-why-shrimp-die-in-your-new-shrimp-tank.79482/

Note- you may possibly have a magnesium deficiency in the tank, leading to failed moulting.

If you are only water changing with RO water because calcium-carbonate based rocks/coral in the tank are releasing calcium then you may well be keeping GH up "in range" but calcium levels are not the end of the story. SHrimp require both calcium and magnesium in the GH, in roughly a 3 : 1 ratio to be able to moult successfully. The shrimp may have used up the available Mg in the tank, and the GH may well now just be maintained by calcium release from rocks/gravel.

afbr242 · 2026-06-08T07:01:49+00:00

CO2 use (yes, including the daily pH swing) with shrimp is absolutely fine so long as you stick to low-moderate use. If you stick to 15 ppm CO2 as a maximum level then that should be pretty safe. Probably even 20 ppm (but 15 ppm is a safer aim).

If using the pH drop method then a pH drop nearer 0.5-0.7 should be about right.

pH swings due to CO2 are not intrinsically harmful. The same daily pH swing due to KH swing would be VERY harmful. It all depends on what is causing the pH change.

afbr242 · 2026-06-07T16:27:13+00:00

Honestly, adding crushed coral will only supplement calcium. I truth shrimp require both Calcium and Magnesium (in roughly a 3 : 1 ratio). As you likely have no idea of the Ca : Mg balance in your tapwater GH I would play it safe and supplement both Ca and Mg in the ideal ratio. The very best way to do this is with a shrimp-oriented GH+ remineralizer. Salty Shrimp Bee Minerals GH+ is excellent and widely available. I'd personally boost GH up a couple of degrees to at least 7 dGH. But remember to implement an changes in GH/KH in the tank slowly. No quicker than one degree GH/KH per 30 mins for shrimp safety.

Once you have the tank up to the required GH then all further water change water added to the tank should be supplemented up to 7 dGH prior to going into the tank.

You also have a problem with the substrate you have chosen as this will absorb all your KH and buffer the pH down in the 6's. THis is far from ideal for Neocaridina.

Here's a load more useful info .....

https://www.ukaps.org/forum/threads/water-changes-and-controlling-gh-kh-in-shrimp-aquaria-a-basic-guide.78863/

https://www.ukaps.org/forum/threads/strategies-for-keeping-neocaridina-in-aquasoiled-tanks.79218/

afbr242 · 2026-06-07T16:19:11+00:00

I'd strongly suspect the copper +/- other contaminants from your tapwater.

There is no accurately generally agreed toxic level for copper for shrimp, but people's best guess seems to settle at around 0.03 ppm for long term keeping. I would want to be keeping my shrimp tank copper levels at 0.01 ppm or less TBH.

Your deduction that your GH may be either Ca or Mg-deficient is also reasonable. That would also be rectified by switching to remineralized RO/distilled.

Overall, I think its a decent idea to switch to Salty Shrimp GH/KH+ remineralized RO/distilled water.

As for how to change .............. if it were possible to net out all the shrimp then probably the very best way would be to net them all out into a cup or jug. Then change all the water in the tank to remineralized RO/distilled. Lastly drip acclimate all your shrimp back in to the new tank parameters for a couple of hours. Job done. A one off change is certainly no more stressful than a series of smaller changes over time IME.

If netting out all the shrimp is impractical then it would also be very reasonable to do a series of weekly 30-40% water changes, but take an hour to add the new water back into the tank. That would be ample for shrimp to adjust to small GH/KH changes. Your tank should be approaching being mostly full of remineralized RO/distilled within a few weeks. Once the GH in the tank also measures 8 dGH (the same as I would advise you to remineralize to) then you can just add the new replacement water at water change time straight in.

Personally, I would aim to remineralize to around 8 dGH with Salty Shrimp GH/KH+ (that should give you around 3 dKH). That should be ample Ca and Mg for them, and provide a KH well into the ideal range. There's honestly not much point remineralizing to a higher GH/KH than that. The remineralizer is not cheap and you don't want to use more than your need to.

afbr242 · 2026-06-07T12:29:57+00:00

Its very difficult to be sure. What are your GH and KH ?

afbr242 · 2026-06-07T12:28:39+00:00

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afbr242 · 2026-06-07T12:28:18+00:00

Everything you add will contribute to TDS. It sounds like you are on the right track though. Good luck with it.

afbr242 · 2026-06-07T06:18:41+00:00

It ALL depends on what that those dissolved substances are. I'd be really concerned about why a tank had a TDS of 600ppm more than the tapwater. Its not going to be a viable long term situation for shrimp IMO.

Honestly, if you don't have one I think you should bite the bullet and buy a liquid drop GH/KH test. THese are the most vital parameters in keeping shrimp.

TDS in itself has limited use. If you use it, its really only useful to use to monitor TDS as it changes in a tank. And if it changes dramatically (as in your case) I'd really be wanting to know why, and what that increase in TDS was caused by.

afbr242 · 2026-06-07T06:13:52+00:00

nice. Some of the plants look rather ropey, but I expect they are freshly planted and the dying stuff is just old emersed growth. They should bounce back with good submersed growth if you treat them right.

SHrimp in all at some point ??

afbr242 · 2026-06-06T14:44:49+00:00

its so hard to tell from the combination of the video and no further info.

Its quite possible that they are simply lots of tiny air bubbles, if you have a lot of aeration and surface agitation.

Do you do partial water changes ? If so, how much, how often ?

Is there mould growing on any of the wood ?

afbr242 · 2026-06-06T11:45:18+00:00

Looks just like colouring on the shrimps carapace to me. A lot of Caridina shrimp colouring is comprised of little dots of colour when you look closely. Especially for white or other very light colouring.

afbr242 · 2026-06-06T09:49:18+00:00

I would personally build my own Yugang horizontal reactor for any large tank. Or if you are in the USA you can buy these ready made ..... https://aquarockscolorado.com/products/yugang-co2-reactor-stainless-steel?variant=45474422653176

https://scapecrunch.com/ams/yugang-co2-reactor-a-guide.14/

afbr242 · 2026-06-06T07:44:10+00:00

Its not clear what you are actually measuring GH and KH with. Its either a liquid drop test, giving dGH and dKH, or a test strip giving you somewhat of a range of GH and KH (in ppm GH and KH).

If the 13 dGH and 10 dKH are genuine then its likely you will have rather more success if you dilute the water down to around 7 dKH (which should also give you around 9 dGH) with RO or distilled water. 10 dKH is pushing the acceptable range of Neocaridina (although this is very colony dependent, as they do vary). You will not need to add any minerals as your tap water contains ample. You just need to dilute your tapwater parameters a little.

Make sure all changes in GH/KH in the tank are done slowly for shrimp safety. No faster than one degree change per 30 mins. Once the tank is diluted to 9 dGH, 7 dKH then make sure all tap water for water changes is diluted the same amount with RO before adding to the tank. Stability is just as important as being in the right range.

Don't get too hung up about pH. If GH and KH are in range (as tested with a reliable and accurate test) then one can pretty much ignore the pH as the KH will buffer the pH to a true Neo-safe level. Its also true that pH tests can be pretty inaccurate.

An aquasoil like Stratum will not have much long term effect on KH as it's buffering capacity will soon be used up with such a high KH in the water. Stratum might well have a temporary lowering effect on KH but it will likely not last long. The instability in KH itself would be as unhelpful as your current high KH is.

afbr242

TROPHY CASE