Cherry Shrimp Tank pH at 8.2

[erbear]

Hi I'm new to shrimp keeping,
I don't know why but the pH of my planted Cherry Shrimp Tank has been very slowly rising from 7.6 in April (when I started it) to 8.2 now.

I've lost 3 shrimp in the last 2 days (2 Berried females and 1 kid shrimp).

I want to know how I can safely and slowly lower it below 8 pH.

Things I've tried:
-Reducing aeration
-Adding Indian almond leaves
-Adding cholla wood

I'm concerned about using peat moss because I hear it can soften water.

I can answer questions about water parameters in the tank and any changes I've made to the tank (I keep everything very well documented).

Thank you so much for your input!

Here is a picture of the tank

 

[JettsPapa]

My shrimp are thriving in 8.2 pH water. I don't know why your shrimp died, but I don't think it's pH, unless the pH change was too rapid for them to adjust to.

 

[erbear]

I'm just concerned because 8pH seems to be the upper limit of what Cherry shrimp like. I agree that they could definitely thrive above 8 given the right circumstances.

Any ideas on why the shrimp would die?

On 5/30 I treated the tank w/ 0.1 gram fenbendazole (dewormer) for planaria. I did an extra water change last week and monitored for ammonia spikes. Everything stayed stable.

 

[JettsPapa]

How big was the water change?

 

[ROFEA]

I cannot see well enough, is the substrate like the shrimp stratum pellets or is it gravel?

 

[erbear]

The substrate is inert gravel (Seachem- Flourite Black).

The water change was 12.5% (1 gal) the day before treatment. Then 12.5% (1 gal) again 48 hours post-treatment.

 

[JettsPapa]

I dunno. Maybe richiep will have some ideas.

 

[richiep]

Thing is you may be having fluctuations in ph from your source water, but first I'd like to know what your gh/kh readings are?
How much and how often you do water changes

 

[erbear]

GH 8 KH 3.

I do 12.5% (1 gal) water change once a week. I use DI water and remineralize with Salty Shrimp GH/KH+. The tank is a 10 gal but the water volume is ~8gal (1gal=12.5%). Thought I should explain the weird percentage.

The pH is down to 8 as of yesterday (checked before my weekly water change). I attribute that to the Indian almond leaf I put behind the matten filter on Monday.

The real mystery is why the pH keeps rising slowly despite the huge piece of driftwood, the cholla wood, and Indian almond leaves in the tank.

I keep TDS around 200ppm btw.

 

[richiep]

The wood and leaf are not going to make things stable and never will as no one knows how much is needed, when it stops lowering, and how much more to put in, so its always gamble this way, the only way to keep it stable is the way you are doing it, can you check your water for ph before reminerilising

 

[erbear]

The DI water I use is pH 6.4.

I hadn't thought of that perspective. I figured that if something is neutralizing H+ in the tank faster than I add it, then I should add more acidifying material. I didn't think of those materials as destabilizing the tank.

So, I should instead be looking at water changes to balance my pH?

I really appreciate the input. I've been racking my brain about this for months.

 

[richiep]

Well that ph is totally wrong any ro water should be coming out at ph7 which is neutral so whats going on ?? Where are you getting the water?
The kh you've got should be stabilising that ph, you need to do a water change with pure ro water but very very slowly you shrimp csn only take a .4 rise at any one time or it will kill them,

 

[erbear]

When water is first distilled it by definition has a pH of 7 but it absorbs co2 from the atmosphere and naturally becomes slightly acidic. I get the water in gallon jugs from the grocery store. It's Distilled water, not sure if it's RO purified.

I don't have access to RO water that I know of.

When the water is remineralized the pH goes up to ~7.6

 

[richiep]

I hold my ro water for a week before using and its still neutral when I use it so not sure on that one once at 7.6 your kh should hold it there with only a point or two move either way, salty bee once mixed should stabilise and ph held by kh, do you know what your gh is, before we move on

 

[erbear]

I'm not claiming to be an expert on the subject, that's just what I've read. And yeah, the KH should stabilize pH.
GH 8

 

[richiep]

OK now to get out of this all top upe should be done with your pure distilled water and thats everytime you top off from now on, before the next water change do as many water tests as possible then do a change with pure distilled water, wait 25hrs then do your taste again things should have changed a little you can do two changes a week to get things moving, now once you've got you water where you want it you start mixing water outside the tank to that of the tank water, you will get used to this using a tds meter as a guide so if your tank is 7.4 and tds is 180 then when you mix you mix it to a tds of 180 this tds guide will put you on the money all the time, now if the tds creaps up to 200 reduce the minerals to a tds of 160 this will put things back to near as norm, you seem to be up to speed with water chemistry so I hope you understand where I'm coming from

 

[erbear]

I think I understand. So, do 2 water changes per week with just Distilled water (no added remineralizer). Get the pH to ~7.6 (I have snails so I need some alkalinity). Then, hold TDS at 180ppm and see if this helps with pH level and stability.

I always mix my water in a bucket and test with a TDS meter before adding it to the tank so that's no problem.

My only concern is not refreshing minerals in the tank during this process. Also, what if the TDS drops faster than the pH?

If I do one pure distilled water change (no minerals) that will bring my TDS down to 175.

 

[richiep]

If you want to mix ½ the minerals you were using then it will just take a little longer to get down which is not a problem as you are not in the danger zone so do as you feel comfortable you can stick to once a week if you want its really down to you, once you get the ph where you want it do a gh test and once you got that do a tds reading, this will become the guide for mixing in the future

 

[erbear]

This is an excellent plan that I never thought of. I will start this week and post how it goes.

I wonder what the pH of remineralized distilled water will be if I only remineralize to 100 TDS

 

[richiep]

I think the affect is minimal but worth a test but it certainly won't be out side the .4

 

[erbear]

Happy shrimp eating a shrimp pellet. The young shrimp are 5 weeks old!

 

[erbear]

Update:
I got my pH to stabilize at ~7.8. TDS is at 185 but I bring it down to 180 after a water change.

Thanks for the help!