Cloudy water after water change

[citymouse]

Hi,
I have 215g tank, did a 40g water change a few days ago and my water has been cloudy ever since.
This is not a new tank, it's been set up for almost a year now.
I thought maybe it was sand since I was cleaning and pushing around sand, cleaned the glass etc. but after 3 or 4 days I would think this would all settle.

I changed the filter socks, I don't run anything else in the tank (in the process of buying a carbon reactor).
I'm not treating the tank with anything.
I have a probe that measures PH and have noticed that's a bit low, at 7.8 if the probe is accurate, I do need to test it myself though, I'm not sure how accurate those probes really are. It's the Apex Fusion with 4 probes measuring salt, PH, ORP (still don't understand this one), temp. However, the water wasn't cloudy like this before the water change.

I have not tested my perimeters...I know...I should have done this by now...but all of my test kits are upstairs with the new QT that I'm cycling and I keep forgetting...life = busy = forgetfulness. Salinity is fine though, that I tested and see on the Apex app.

Anyway, is there any reason for this sudden cloudy water right after a water change? I read some thing about bacterial bloom, but why would that happen immediately after changing water in a well established tank? could it have anything to do with my water? I have an RODI water set up, mix the water and salt in Brute cans, run a pump in one and a couple power heads in the other to mix things up, heaters. I had let this sit for 3 days before doing the water change..mostly out of procrastination and not having time, but that salt should have been thoroughly dissolved.

I have 2 clown, a snail and about 10 hermit crabs. No corals.

 

[Dr. Reef]

my guess would be bacterial bloom or alk precipitation

 

[citymouse]

Update: I just tested. Ammonia =0 Nitrite =0 Nitrates =0 (using API test kit)
PH 7.8 KH 6 Why is the KH so low? Is this okay, do I need to do something to raise that? I thought it was usually the same as PH?

 

[citymouse]

my guess would be bacterial bloom or alk precipitation

what is "alk precipitation"?

 

[Dr. Reef]

what you are seeing is most likely calcium carbonate precipitation due to addition of high pH Alkalinity saltmix water being added to your lower pH and alk water in tank.. I suspect alkalinity in the make up water is much higher than tank water.
By the way 6 dkh is low and it needs to be brought up. Acceptable range is 7-11 dkh with caution not to increase 1 dkh per day.
pH results and alk is not same thing. pH is directly related to co2 present in the water while alk is buffering capacity/ neutralizing acid.

what are your cal and mag values?

 

[citymouse]

what you are seeing is most likely calcium carbonate precipitation due to addition of high pH Alkalinity saltmix water being added to your lower pH and alk water in tank.. I suspect alkalinity in the make up water is much higher than tank water.
By the way 6 dkh is low and it needs to be brought up. Acceptable range is 7-11 dkh with caution not to increase 1 dkh per day.
pH results and alk is not same thing. pH is directly related to co2 present in the water while alk is buffering capacity/ neutralizing acid.

what are your cal and mag values?

Thank you!!
How do I bring up the KH? I have cora, gro but I'm using it as part of cycling my QT and there isn't enough for the big tank.
I have no idea what my cal and mag values are, I've never tested and don't have a test for that...should I? I don't have corals if that makes a difference.

Is this low KH dangerous to my fish and hermit crabs? I've never had this happen before, I had a 75g tank for 7 years before this, only issue I ever had in there was algae growth!

 

[LouisianaReef]

With you tank be a FOWLR tank the cal and mag isn't as important as if you were to have a full blown reef. But alk, cal, and mag are all tied together un generally all have to be maintain in order to keep them in proper levels.

 

[citymouse]

I researched how to raise the KH using baking soda, found a calculator to figure out the right amount etc. I added tested again and then added that tonight, I was still at 6 prior to adding, hopefully I see some change tomorrow.
I need to buy new test kits and supplies for each tank, I'm thinking I need to include some new ones I never tested for in the past!

 

[LouisianaReef]

Nothing wrong with using baking soda to raise the ALK. But on a side note, if you baked the baking soda first, it will cause the ph of your tank to raise after dosing (Not sure which method you used). Which will level off after some co2 enters the tank. I'm not sure how important if with you not having coral in your system, but it is generally acceptable to raise the alk 1 dkh per day until it is at the correct levels to prevent shock.

 

[citymouse]

Nothing wrong with using baking soda to raise the ALK. But on a side note, if you baked the baking soda first, it will cause the ph of your tank to raise after dosing (Not sure which method you used). Which will level off after some co2 enters the tank. I'm not sure how important if with you not having coral in your system, but it is generally acceptable to raise the alk 1 dkh per day until it is at the correct levels to prevent shock.

I just mixed it in water to dissolve it, I added only enough to raise it up 1 dkh, according to the calculator I used. I'm trying to figure why the KH would have dropped so low to being with, but it will probably remain a mystery and hopefully raise back up to normal levels again. Typically it's between 7 and 9, so I'm not that far off, even though it's low. I'm just glad I caught it before my tank crashed.

 

[Dr. Reef]

some tanks can consume up to three dkh per day. Those are usually heavily stocked tanks. You don't have anything in your tank and are still cycling. Even then alkalinity can be used up by bacteria and some types of algae is like coralline algae. So you will have to watch your tank and see how much it declines and dos accordingly.

 

[citymouse]

some tanks can consume up to three dkh per day. Those are usually heavily stocked tanks. You don't have anything in your tank and are still cycling. Even then alkalinity can be used up by bacteria and some types of algae is like coralline algae. So you will have to watch your tank and see how much it declines and dos accordingly.

My tank isn't still cycling though, it's been set up for almost a year, everything has been good until now, but I have been battling some unwanted algae, reddish brown all over the sand and there was some hair algae but oddly it was mostly only on the WAV's, so that's pretty much gone now.

I'm wondering if it would be helpful to keep a chunk of limestone/holy rock in the sump? Has anyone ever tried this? I'm realizing the reason my old tank probably never had a drop in KH was because I had a big holy rock in there, surrounded by live rock...my clown fish made it theirs! The tank was converted from fresh to salt and I had just left that big rock in there.

 

[brandon429]

how can you be sure its not stirred up sand silt causing the cloud just checking there on that option

 

[citymouse]

how can you be sure its not stirred up sand silt causing the cloud just checking there on that option

I thought that at first since I had just changed the water and attempted to clean up the sand, but it's been a week a now and tank is sill cloudy, plus my KH is low and what people are saying about Alk precipitation sounds like the issue. Normally doing a water change and messing with the sand, doesn't cause this much cloudiness for this long.

 

[brandon429]

sounds good but on low alk id not suspect the precip, but high alk I would

low alk should register as marked diurnal pH swings.

 

[citymouse]

sounds good but on low alk id not suspect the precip, but high alk I would

low alk should register as marked diurnal pH swings.

Honestly, I have no idea how any of this works, I learn when issues arise and I come here for help .

So, what I understood from these comments, was that when I changed the water, the new water had a higher KH than the tank water and this caused to cloudiness or alk precipitation? Which i had never heard of before now.
Before the water change, my water was fine, not crystal clear but not noticeably cloudy. When I've done water changes in the past, there would be a little cloudiness from disrupting the sand etc. but it would settle after a couple hours, never lasting thru to the next day.

I've never seen my tank look like this before, other than when I first set it up and the sand was new.
The PH is currently 7.8, I haven't noticed any major changes in that, but again, I don't test it regularly. I do have a probe in the water via the Apex Fusion, I think it alerts to any issues, but I've never had it do so.

 

[citymouse]

Honestly, I have no idea how any of this works, I learn when issues arise and I come here for help .

So, what I understood from these comments, was that when I changed the water, the new water had a higher KH than the tank water and this caused to cloudiness or alk precipitation? Which i had never heard of before now.
Before the water change, my water was fine, not crystal clear but not noticeably cloudy. When I've done water changes in the past, there would be a little cloudiness from disrupting the sand etc. but it would settle after a couple hours, never lasting thru to the next day.

I've never seen my tank look like this before, other than when I first set it up and the sand was new.
The PH is currently 7.8, I haven't noticed any major changes in that, but again, I don't test it regularly. I do have a probe in the water via the Apex Fusion, I think it alerts to any issues, but I've never had it do so.

Actually, I just checked the app and my PH is 7.91 today, last night it was 7.8. Looking back through the history, it has stayed between 7.8 and 7.95

 

[citymouse]

KH is now up to 7 but the water is still cloudy.

 

[citymouse]

Still cloudy just over a week later! Everything is fine, am. 0, nitrite 0, nitrate 0, PH 7.8, KH 8. Nothing has happened to cause the tank to re-cycle, it's been a year and I've no issues, only 2 fish and handful of hermits.

Any new suggestions? I don't know what is going on or what to do about it. This happened right after my water change, everything was good before that. I also test my RODI water, nothing wrong there either.
I'm stumped.
Just got my carbon reactor today, carbon should be here tomorrow, but I feel this isn't going to solve this particular issue.

 

[Djkarp]

Did you figure this out?