Sudden Ph spike in RCS tank

Hi all,

First post here. I am new to keeping shrimp and have limited experience with fish. My girlfriend used to keep cichlids. We currently have about 10 shrimp and a little pleco (who is waiting to be moved to a 20 gallon tank when we move apartments and then cycle the new tank. We were misled about her requirements and are making changes as soon as possible).

We have had the tank for about two months. Our shrimp were doing well, I think, though we had two casualties, both died the day after we added them to the tank. This past week we had our first baby shrimp sightings. The adults seem busy so we think they are happy.

We have had some trouble learning how much to feed them (suddenly we had snails and tiny worms on the glass) and the pleco but I thought we were finally dialing it in. Yesterday we vacuumed up a lot of the pleco poop for the first time, changed about 1/4 of the water and changed the carbon part of the filter.

I’ve been testing the water before and after each water change and periodically throughout the week just to learn what is normal and keep my eye on things.

Last night after the water change, things were stable. This morning, I tested and the pH had gone from 6.4 to 8.4 and the KH had gone from 0*d to 20*d!!! And one of my shrimp was dead with a white ring. The others are being sedentary and not zooming around the tank or nibbling along the bottom.

I think it is from the new carbon but we rinsed it in tap water and than syphoned off tank water.

My questions are: what do I do about the pH? I am scared it will kill my shrimp and pleco. But I am also scared if I change more water that it will kill them.

Going forward, how do we keep the pH from spiking??

Other details: I have Java fern, Java moss and Christmas moss in the tank. Last week we put in a piece of Cholla driftwood that we boiled first.

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Tank
What is the water volume of the tank? 5 gallon
How long has the tank been running? Two months
Does it have a filter? Yes, aquaclear 20
Does it have a heater? Yes
What is the water temperature? 78*
What is the entire stocking of this tank? (Please list all fish and inverts.) 10 sunkist shrimp, one pleco

Maintenance
How often do you change the water? Every two weeks
How much of the water do you change? 25%
What do you use to treat your water? Stress coat
Do you vacuum the substrate or just the water? First time vacuuming yesterday

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? 6 in 1 strips and a separate Ammonia kit.
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 100 (this never changes, even after water change?? Why?)
pH: 8.4!!!

Feeding
How often do you feed your fish? Every other day
How much do you feed your fish? Idk how to quantify that? Three or four pellets, or a few granules, and one waf
What brand of food do you feed your fish? Tetra and API
Do you feed frozen or freeze-dried foods? Idk? I feel them Pleco Wafers, Tropical Granules, and Bottom Feeder pellets.

Thank you in advance!!

 

Welcome to Fishlore

I have to wonder if maybe your test strips aren't telling you the truth. I can't see how water changes aren't lowering the nitrates unless they are this high straight out of the tap and how your pH and kh could have changed that drastically. Have you tested your tap water with the strips?

I have to think if your nitrates are really this high your shrimp wouldn't be healthy and breeding at all. If at all possible I will suggest you upgrade your test strips to an API Master Test Kit.

 

A sudden ph swing of that much will kill shrimp
Take mattgirl advise

 

Welcome to Fishlore

I have to wonder if maybe your test strips aren't telling you the truth. I can't see how water changes aren't lowering the nitrates unless they are this high straight out of the tap and how your pH and kh could have changed that drastically. Have you tested your tap water with the strips?

I have to think if your nitrates are really this high your shrimp wouldn't be healthy and breeding at all. If at all possible I will suggest you upgrade your test strips to an API Master Test Kit.

Thank you! I’m on my way to the store now. I’ll get another kit and test the tap and the water again.

A sudden ph swing of that much will kill shrimp
Take mattgirl advise

How do I bring it down?

 

Thank you! I’m on my way to the store now. I’ll get another kit and test the tap and the water again.

The API liquid tests are often much more reliable than the test strips.

How do I bring it down?

First let's find out if it actually spiked that high before we do anything.

 

Don't do anything drastic, as mattgirl says you need to find out if you have a problem

 

Aaahh... just came home from the store. They didn’t have a kit with everything but the guy there tried to help. I just got home and realized that he didn’t give me anything for nitrate/nitrites. He sold me another ammonia kit and a pH kit.
The API pH has the pH at the darkest 7.6 and my water straight out of the tap somewhere between 6.6 and 6.8 (it’s hard to call which color is closest)
He also gave me Cholla wood.

 

What kind of decor do you have in this tank? Is any of it by any chance limestone or coral? Either of those will affect your pH and possibly kh. Have you added any kind of new decor to this tank recently? Something spiked it. We need to figure out what it was.

I see the pH kit comes with both pH up and pH down. Please don't use either one until we get to the bottom of why both numbers spiked.

Hopefully richiep will help me out here with numbers but if it were me I would start doing water changes. When replacing the water I would be dripping it in instead of pouring it. I use a piece of airline tubing with a control valve on the tank end of it. It can take an hour or more, depending how much water I am changing in my 2.5 gallon shrimp bowl, to replace the water.

First though, check to see what if anything in this tank could be affecting the numbers.

 

What kind of decor do you have in this tank? Is any of it by any chance limestone or coral? Either of those will affect your pH and possibly kh. Have you added any kind of new decor to this tank recently? Something spiked it. We need to figure out what it was.

I see the pH kit comes with both pH up and pH down. Please don't use either one until we get to the bottom of why both numbers spiked.

Hopefully richiep will help me out here with numbers but if it were me I would start doing water changes. When replacing the water I would be dripping it in instead of pouring it. I use a piece of airline tubing with a control valve on the tank end of it. It can take an hour or more, depending how much water I am changing in my 2.5 gallon shrimp bowl, to replace the water.

First though, check to see what if anything in this tank could be affecting the numbers.

Thank you!! I have another piece of cholla, a rock, two pieces of coral that have been in since the beginning, and some snail shells. Yesterday we vacuumed (which I was afraid would raise the ammonia but there was pleco poop everywhere) and changed the carbon part of the filter.

I’m attaching a picture. The heater isn’t plugged in. I was told it wasn’t necessary if the temperature is steadily in the 70’s.

 

If at all possible you may want to go on amazon and order the full API kit. It has test for both high and normal pH. I know the guy at the store was just trying to help but I don't think the cholla wood is going to help this situation.

Thank you!! I have another piece of cholla, a rock, two pieces of coral that have been in since the beginning, and some snail shells. Yesterday we vacuumed (which I was afraid would raise the ammonia but there was pleco poop everywhere) and changed the carbon part of the filter.

I’m attaching a picture. The heater isn’t plugged in. I was told it wasn’t necessary if the temperature is steadily in the 70’s.

I can't imagine why it would have taken this long for the pieces of coral to start affecting your numbers but if it were me I would go ahead and remove them. It is possible something changed about the chemistry of your tap water and it is now reacting more with the coral. Temp seems to be fine. Mine stays at about 72 most of the year. It will go up once Summer gets here.

I don't think changing the carbon or vacuuming would have caused what we are seeing. I actually don't run carbon in any of my tanks. It really isn't necessary unless we are having to remove medications or if our tank start not smelling so good. The space the carbon takes up would be better used for more bio-media.

 

Thank you so much for your help!!!

I googled coral and pH after your last comment and took it out. I had no idea it could affect the tank. (I have so much to learn!!)

My pleco is **** as the coral was her cave. She’ll have to deal until I can find something else.

Preparing for a water change now. I have a little bit of tubing that I’ll use like you suggested. Fingers crossed.

 

You are so very welcome.

Even though I have been in this hobby for a very long time I am still learning. I don't think we will ever learn every thing there is to learn. Hopefully removing the coral will stop the spikes. I would only be changing out 25% of the water each time but would be doing it daily until the numbers are back down where they were before the spike. You could do it twice in one day but give it a few hours in between each one.

 

Sorry I'm late to the party taking the coral out is the right advise from mattgirl id do one water change and give it 8hrs and do a ph test and post the results before you go further, the secret now is not to be drastic with anything that could upset things

 

Thank you both! Water changed done about 4 or 5 hours ago. No change on the pH. I’m going to bed in a few and I’ll test again in the morning. I’m so worried about my little critters.

 

Another water change yesterday. I don’t think the babies survived but the adults are still there. Still a little sedate and some are hiding but that might be because the pleco lost her house.
The strips are showing things are back to normal but the API kit is still high. I wish I had used the kit to get to know a base line cause now I’m not sure what my are little shrimp are used to.

 

Don't worry to much about the shrimp as long as things like water changes are done really slow they will.adapt to new conditions
If your strips show things normal and liquid shows high I wonder how high things were before you started using liquid tests