# How to control TDS creep?



## Iwagumi_Scaper (8 Sep 2018)

Hi all,

So I'm aware of TDS creep and in my low tech tank it was never a problem however, in my planted tank it just keeps creeping up, despite doing 50% water changes weekly. Started at 250 TDS when the tank was set up, and is now at 559 3 weeks after starting ferts dosing. Is this a problem, and what do the rest of you do?

Part of the reason I ask is that I've had two Amano shrimp disappear over night, completely unexplained - the tank is covered so I don't know how they got out if they did.

Many thanks,

Chris


----------



## tam (8 Sep 2018)

Doing 50% changes it should settle about 3 changes in and remain steady but higher than the source water, if you are dosing/changing the same each week. You can do the maths to work out what that equilibrium point will be using TDS of source water, tank volumn and TDS increase after dosing.

Things to check would be that you are actually changing 50% - you can check this by measuring tank TDS before/after change and the water you use to change. 

Substrate, rocks etc. can also increase it if they leach things.If you lose a lot to evaporation and top up with tap (not RO) that will also contribute, but again if it's all a steady increase over the week it should be evened out by 50% water changes.


----------



## sciencefiction (8 Sep 2018)

Yes, it is a problem for the long term health of the fish...A steady, healthy range for the fish species TDS is pretty much the most important factor in keeping fish. 

Water changes is the only way to get the TDS down and perhaps you shouldn't be dosing that much either. I got back from a 3 week holiday without any water changes and the TDS had crept up by only 50ppm but that is actually a lot and it takes a good few large water changes to get back down considering my starting point is similar to your water.


----------

