Very High TDS

[Mathman]

Hi, 

Have a strange problem and hoping for some help. I have a 30-gallon planted tank with a sponge filter and an additional internal filter.

The issue is the extremely high TDS as measured by my meter as over 2500 ppm. My current stock of fish and inverts seem to be doing fine. I had no cherry shrimp, and when I added 10 last week (drip acclimated for 5 hours) they were all dead by morning. I only have neons, nerite snails, kuhli loach, pygmy corys, and pygmy snowball pleco, so I can't imagine they are the reason.

Per Aquarium Coop test strips, Nitrates 10, Nitrites 0, Gh 150, Kh 40, pH ~7.0.  Tested ammonia at 0.

I tried water changes (30%) with tap (~550 TDS) and distilled water with no real change in TDS. At a loss on how to proceed. Hate to do too large a water change and lose current stock.

Any help would be appreciated (Would love to add shrimp!)

Paul

[billango]

Probably a longshot because that TDS is so high, but if you're using a substrate that might be adding to your TDS like aragonite you could try replacing or capping it with something neutral and see if that helps at all. Good luck. 

[SugarBassJoe]

I would just use straight tap water for your water changes, it will take a while to lower your tds if its really that high (which seems really abnormal to me, are you adding anything to your water?) but you'll want to slowly lower it to avoid losing your other inhabitants from shock.  you can always use RO water and add minerals to get it to the desired parameters, but that could get expensive and you'll still want to lower it slowly. I struggled with cherry shrimp at the beginning too, it seems any change at all would trigger a die off, I would use RO water and add the minerals for water changes, or mix it with tap water always chasing the perfect conditions, special foods just for shrimp, but once I took a step back and worked with what I had things became a lot easier and I had more success. 

[meadeam]

I would really want to know what is driving your TDS.  

Before you started mixing in distilled water had you been topping off your tank a lot straight from the tap?  With TDS as high as your tap has, if you are replacing evaporated water on a regular basis then whatever is in there will be accumulating in the tank.  

[Mathman]

Thanks for all the replies. The suggestion about substrate is interesting. I have crushed coral mixed with my gravel. Too much? Also on the topping off, I see that would not remove minerals and such that are accumulating. Will begin with modest water changes and substrate modification.

Paul