Sudden NO2 spike and cloudy water in the morning

NielsC

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Hello everyone

As of a week, I've been noticing something weird in my tank.
In the morning the water looks very hazy, with a white hue. I can almost see it physically move around in the flow.
By the time I get back from work, the water is (almost but not 100%) crystal clear again. And then the cycle starts all over again. Suddenly I started measuring the ever so slightest amount of nitrites again too...

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Having a RSM Nano, started it up now over 3 months ago. Life stock: a pair of occelaris', a Gramma loreto, three Torchus snails and one little sand sifting seestar. I also bought two cheap frags, as a sort of indicator organism: a Ricordea and a Montipora. Replaced the original skimmer with a Tunze 9001, added an extra power head of 1000 g/h. Using the Red Sea micron filtersocks (they get cleaned every 2-3 days) and I'm also using some reef spec active carbon. I'm using a glass cover to prevent the fish from jumping out, though this will be replaced by a sort of "netting" thing from Red Sea. Doing weekly 15% waterchanges with aquaforest reef salt. Water gets made in house with a mixed bed ion exchanger.

Water values
Ammonia: Nothing measurable
NO3 : 10
PO4 : <0.03
KH: 8.2
Ca: 420
Mg: 1400
Salinity: 1.025

The next two worry me a bit..
pH: 7.7, which is too low.
NO2: the ever so slightest coloration with my salifert test, so <0.1, but not zero.

The fish look healthy, eat well, are swimming around vividly and don't seem to be bothered about this at all (no heavy breathing, no weird behaviour, etc)
The two corals look happy as well, with the Monti looking very nice and fluffy with good polyp extension.
The star is also doing a good job of going through the sand. When it comes to the snails... That's a different story.

I bought 4, but one was already dead in the bag when I got home, which could have been an indication already.. The other three looked fine, but two of them went missing only days after introducing them. It's a small tank but I cannot seem to find them anywhere. I've been looking and searching in the weirdest angles, but nothing.. I also cannot seem to find any empty shells laying around on the sandbed either. The third one looks happy and is doing its job very well.

Three things:
- is that sudden spike in nitrite maybe a sign my two missing snails are actually decaying somewhere? Could it be that my little tank isnt established enough to deal with both the fish waste and this, causing the little amount of nitrite I can measure?
-Can my low pH come from the fact that I'm using a glass cover. Maybe this causes insufficient aeration -> lowers the pH?
-the cloudiness... Because it always seems to start at the end of the night at first I suspected it was coming from spawning snails, but it's going on for a week now, which sounds too long for me? It could also be a bloom of some sort of bacteria maybe? But I've never heard that this happens systematically overnight and clearing throughout the day.

Any thoughts? It is stressing me out a little bit right now, as I cannot seem to figure out what is going on and because "my enemy" is of the invisible kind, rather than algae or something else.
Any tips? What I was planning to do anyway is continuing the weekly maintenance and especially giving my tank time by not adding any animals (mostly talking about corals now, because fish wise I might be pushing the boundaries already) untill the situations "clears" ( ;) ) .

Thank you very much for taking the time to read all of this.

Best
Niel
 

EmdeReef

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White, milky water is usually caused by a bacterial bloom. The fact that it partially goes away is probably a good indicator that it could be bacteria. I would do a larger water change to see if that helps. Are you by any chance dosing any carbon source? If so I would discontinue.

The blooms aren’t as dangerous as long as there’s enough flow to keep the water aerated as there is a risk of O2 depletion.

NO2 isn’t too toxic in saltwater, particularly at 0.1ppm which could be a testing error too.

7.7ph is ok, likely caused by excess room CO2. There are ways to test this. If the glass top is tight enough I guess it could be contributing to this.

IMO a glass top is not a good solution for a reef tank as it will inhibit gas exchange.
 

Katrina71

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Drop in an airstone to give your fish some relief. Water changes. Btw, I've had a similar experience twice when the seasons changed and my heat started coming on. This year I proped my tank lid open just a bit and ran an airstone as a preventative measure.
 
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NielsC

NielsC

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White, milky water is usually caused by a bacterial bloom. The fact that it partially goes away is probably a good indicator that it could be bacteria. I would do a larger water change to see if that helps. Are you by any chance dosing any carbon source? If so I would discontinue.

The blooms aren’t as dangerous as long as there’s enough flow to keep the water aerated as there is a risk of O2 depletion.

NO2 isn’t too toxic in saltwater, particularly at 0.1ppm which could be a testing error too.

7.7ph is ok, likely caused by excess room CO2. There are ways to test this. If the glass top is tight enough I guess it could be contributing to this.

IMO a glass top is not a good solution for a reef tank as it will inhibit gas exchange.

Hi

First of all thanks for your view on the issues in facing. Situation was the same yesterday and today: when I leave early (only the moonlight on) the water is clear. When the whites start to pop up the water gets cloudy, and by the time I get home from work it's as good as clear again. Because of the cyclic pattern, I didn't really expect it to be a bacterial bloom of sorts.

I'm not dosing anything right now, but I have a filtersock with some active carbon in my rear sump.

I'll preform a larger WC then ~ 50%? and see where that takes me.

Running a Tunze 9001 skimmer, on top of over 1200 g/h of flow in my little tank. Should be sufficient, no? However, just as a safety backup I'll also buy a little airstone in case things go downhill. And the glass cover I'll replace asap too. Apart from the obvious downsides(blocking light, blocking gas exchange) of it, it's also visually not very appealing.

In this case I also did a negative control NO2 testing of some newly prepared saltwater. The ready was definitely 0, which imo rules out a testing error? As long as it's this low of a value (and I don't measure any ammonia) I shouldn't worry about this too much then and also have faith in the denitrifiers taking care of it?

Trying to avoid the UV route, for several reasons. I don't have a real sump so I wouldn't even know how to plug one on to my system. if the issues dont go away by itself I guess I won't have a choice though.

To summarize:
-do a large waterchange
-replace glass cover with the "netting kinda type lid"
-put in an airstone for extra aeration
-patience
-if it doesn't clear: filter over UV.

Thanks for the input guys. Will keep this thread updated. If anyone has something to add, please feel free to do so!
 

EmdeReef

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Hi

First of all thanks for your view on the issues in facing. Situation was the same yesterday and today: when I leave early (only the moonlight on) the water is clear. When the whites start to pop up the water gets cloudy, and by the time I get home from work it's as good as clear again. Because of the cyclic pattern, I didn't really expect it to be a bacterial bloom of sorts.

I'm not dosing anything right now, but I have a filtersock with some active carbon in my rear sump.

I'll preform a larger WC then ~ 50%? and see where that takes me.

Running a Tunze 9001 skimmer, on top of over 1200 g/h of flow in my little tank. Should be sufficient, no? However, just as a safety backup I'll also buy a little airstone in case things go downhill. And the glass cover I'll replace asap too. Apart from the obvious downsides(blocking light, blocking gas exchange) of it, it's also visually not very appealing.

In this case I also did a negative control NO2 testing of some newly prepared saltwater. The ready was definitely 0, which imo rules out a testing error? As long as it's this low of a value (and I don't measure any ammonia) I shouldn't worry about this too much then and also have faith in the denitrifiers taking care of it?

Trying to avoid the UV route, for several reasons. I don't have a real sump so I wouldn't even know how to plug one on to my system. if the issues dont go away by itself I guess I won't have a choice though.

To summarize:
-do a large waterchange
-replace glass cover with the "netting kinda type lid"
-put in an airstone for extra aeration
-patience
-if it doesn't clear: filter over UV.

Thanks for the input guys. Will keep this thread updated. If anyone has something to add, please feel free to do so!

Sounds like a good plan. Based on what you describe it does seem like a bacterial bloom. Perhaps adding some nitrifying bacteria (biospira or similar) may make sense.

instead of an air stone I would add a wave maker and point it to the surface. Air stones don’t move enough water.
instead of an air stone I would add a wave maker and point it to the surface. Air stones don’t move enough water.

UV is optional, this will likely clear by itself once your tank stabilizes more. Good luck and keep us posted!
 
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NielsC

NielsC

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I was actually thinking about adding some spores to the tank, but with a possible bloom going on right now, I didn't want to make the situation any worse and I cannot really foresee what the effect would be short term.

I have some Red Sea Nitrobac laying around. It's a mix of Nitrifiers and denitrifiers. I could have a go with this?

Thanks again for your opinion :) greatly appreciated!

PS: I amped up the surface flow once more with an extra little wavemaker I had laying around. Total flow in this 20G is now over 1600 g/h. Sounds like a lot but the Monti seems to love it, and the fish don't seem to mind it. Monitoring the situation closely though. If necessary I can always tune the powerheads down a little.
 
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NielsC

NielsC

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Little update from my part:

Preformed a 50% WC and added some extra bacteria to the tank. First few days: same situation. As of yesterday, it seems to be clearing up, massively!

So it's defenitely going in the right direction.
 
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