Tank crashing

[hashbrown1408]

Hi all, sadly my tailspin blenny passed away.
I checked water chemistry for my 25g nano:

Phosphates 0.42
Ammonia less than 0.02
Nitrates 3.2
Alkalinity 3.7

All other fish and inverts are healthy and corals look happy )

I ran phosphoguard but it hasn’t seemed to help.
Does anyone have an idea of what might have caused these drastic changes? This is the second time I noticed this happen (luckily the first time no fish or corals were lost)
I run lights for 8hrs and then refugium for 12hrs O/N and do a 20% weekly water change in addition to dosing all for reef.

 

[Katrina71]

Is your water cloudy at all?

 

[hashbrown1408]

Is your water cloudy at all?

Not cloudy but I did notice in the past few days my copepod population has exploded I can see them all in the water column all day

 

[Katrina71]

I would suspect a bacterial bloom honestly. Maybe not, but years ago my tailspot was the first to go.

 

[Mppp]

Phosguard is wicked strong stuff so I wouldn't go too nuts and test daily or every 2 days for next week minimally until you reach .15ppm or less. The alkalinity level being so low is weird to me. You were right to do only 20% imho on such a small tank and it will only barely affect the phosphate level so I think the main thing is take it slow in your reversal process as you haven't seen to lose anything. If you do too much of a water change you may get a cyano breakout as your nitrates may bottom out. I've never had the reverse problem of nitrates being lower than phosphates ( I can't say this is the worst news ever), but again just keep eye on phosphates as you're using phosguard as it DOES WORK and it's strong so may be a day or two before you see phosphates come down in testing. Maybe dose a bit of soda ash to start bringing up alkalinity and I am curious what your calcium and magnesium levels are as well. If you had a copepods explosion I wonder if you added too much phytoplankton as it does add phosphates.

 

[Mr. Mojo Rising]

What drastic changes do you mean? One fishing passing away but everything else happy? That’s not a tank crash. Sort of exaggerated there eh lol