I am new to caridina shrimp keeping and recently finished cycling two tanks, 5G and 20G long. I just purchased 8 CRS and 5 shadow panda (they are in separate tanks). When I brought them home the store water TDS was on the low side ~95. So before adding them to my tank I lowered my TDS to about 105. It's been about 4 days and the TDS seem to be going up about +10 every day. I have changed water 2 times already (~20%) to keep the TDS around 110. Is this right approach? Should I constantly change water to keep it at 110 and until TDSs stabilizes? Any idea why the TDS is going up? Any help will be appreciated.

Tank info: I am using RO water and mineralize with GH+. Substrate is Fluval stratum and have christmas/Java moss and Java fern tied to rocks. KH 2; GH 6. I feed bacter AE and snow pop.

Edited November 30, 20196 yr by endeavor

KH should be 0

Do you know what kind of rocks the java is tied to?

Bacter AE could be causing a rise in TDS

Any other rocks in tank? Or coral?

8 hours ago, endeavor said:

rocks

It's almost always rocks that cause TDS to rise.

Zoidburg is on the right track. 

Remove the rocks. Test it in a bucket of water. Check the tDS before adding the rock, and test the TDS again after a few hours with the rock in the bucket. 

 

TDS will rise due to normal evaporation as well, though probably not by 10 per day this time of year? Topping up between water changes should be done with just RO water (no added GH+).

Don't keep changing the water to keep chasing the TDS figure you want. Hopefully we can sort it out fairly quickly?

As above there is a likelyhood the rocks are the problem or a combo of the 2?

Simon

It's Seiryu aquarium rock. I did some reading on this type of rock and you guys are spot on, they are not meant for soft water tanks. I will remove the rocks, hopefully that will help with TDS and keeping the KH and GH low as well. I am going to replace the rocks with Cholla wood, can too much cholla wood be bad for soft water tank? I am talking 10 to 12 cholla wood (8 inch pieces) with moss/fern tied on them in a 20G.

Related question, can I move the rocks to my other tank with inert substrate (has only cardinal tetra, pearl gaurami and neocaridina shrimp)? 

I don't think the cholla wood would be a problem though that is a lot? You can use Lava rock if you want some rock, or driftwood, they are the usual STAPLES of lots of shrimp tanks and give a variation of textures to look at?

If you put the rock in with the other fish etc just keep a close eye (easy enough with a TDS meter) to be sure it doesn't take the figures too far out. Cherry shrimp are tougher and more adaptable and you can soon whip it out if it looks like it is starting to get out of line? 

Simon 

I had the same problem with rock. I won’t ever use rock without a muriatic acid test from here on out. 

The rocks ought to be fine in the other tank.

 

I was thinking evaporation at first as well, but based on the information, I figured there was probably something more going on.

 

As with anything, keep an eye on the parameters. Fluval isn't considered one of the best substrates out there and there's a chance that the buffering capacity isn't working well due to the KH being in the tank. It might need to be replaced to keep a low pH tank.

Thank you. I have replaced the rocks with Cholla wood and did a 30% water change. Hopefully, this should stabilize the TDS and lower the PH even further (its 6.4 currently).

I am noticing that the shrimp are molting frequently since I added them on Wednesday, is this sign of stress? Out of 10 shrimp I have already seen 4 molts.

Tank info: I am using RO water and mineralize with GH+. Substrate is Fluval stratum and have christmas/Java moss and Java fern. TDS 140; PH 6.4; KH 2; GH 6. I feed bacter AE and snow pops.

Edited December 2, 20196 yr by endeavor

It's normal for them to molt in new tank parameters... but you don't want them molting too frequently.

With RO water and GH+, your KH should be 0.  Is the 2 KH due to the rocks?

54 minutes ago, beanbag said:

Is the 2 KH due to the rocks?

Yes, almost certainly due to the seiryu rocks.

 

Those parameters look good now so lets hope it is fine from  here on. The KH will slowly drop as when you do a water change you will be extracting KH2 water and adding KH0 but don't get too carried away with water changes, once a week about 10% should be fine. Changing water will induce molting as well. Where you are with TDS is perfect as it is mid  range, 100 was a bit too low. GH, as with KH may drop 1 over time as well as the new water will likely have a lower number than the GH6 you are removing.

Simon