How to tell if beneficial bacteria was wiped out in a tank crash...

[2wheelsonly]

Reef vets, I need your help.

I am trying to figure out how "toxic" and devastated my water column is after my tank crashed. A very long story, I used Flatworm Exit not realizing how many flatworms were hidden away and wiped out my entire 300g tank. 100% loss of corals/fish in a matter of 12 hours even after massive water changes and double the carbon.

I am trying to determine if there is an easy way to understand how much beneficial bacteria is left in my tank and if I can consider it "mature" anymore?

My current params:

Ammonia: 0
Nitrite: 0
Nitrate: 20 (this is very high for me, normally am at 1 struggling to raise it)
Phosphate: 0.11 (again normally 0.01 on a hannah ULR checker, so very high)
Alk: 8.8
Calc: 410
Mag: 1350
Temp: 77.8
PH: 7.9 (normal for my house)

If I have nitrates, is that a sign my bacteria is doing it's job? If wiped out would I see more ammonia and nitrites?

My goal is to do several large water changes every two days; re-arrange my rock work and start stocking the tank again in a month starting with fish and moving to SPS in month 2-3. Not sure if this is a mistake or not; I fear if I wait longer the tank will get more and more neglected as I contemplate quitting the hobby and ripping this beast out of my wall.

 

[homer1475]

If you have 100% die off, and there is nothing living in the tank, I would just dose the tank with pure ammonia to stress test the biofilter. If you can clear 2ppm ammonia in 24 hours, your biofilter is fine.

I would think with the mass die off you had and your parameters still seem in check, your biofilter is probably fine.

 

[jda]

You did not kill all of it. It will come back once you get everything under control. It might take a while.

I don't know of any way to see if it is still functional other than to keep on testing nitrate and see if it starts to drop again - if so, then you anoxic bacteria is working again. Zero ammonia and nitrite means that the oxic bacteria are working well.

I would avoid chemicals or you could just inhibit the growth. Water changes are probably good.

 

[jda]

Off topic, slightly... but plan to treat for the flatworms a few more times. They can hide out in powerhead cord inlets, rock (or wherever) and can populate again. Three or four more times should get them all. If you ever seem them again, treat them ASAP - this should be easy since you know what to look for. The medicine is quite safe, but as you found out the flatworms are not. The tank can easily handle some of them, perhaps even thousands, but tens of thousands or more are a huge issue.

It might be good to wait and treat a few more times before you repopulate the tank. Declare war on the worms - this can motive you for a while. You can also turn your lights off for a while and when you turn them back on the rock and everything should be sparkling clean and ready to reboot.

Levamisole is the same product as Flatworm Exit - it is a livestock dewormer. You can buy a pouch from eBay. One level teaspoon in a 500ml water bottle - 1 ml per gallon to treat. You can do thousands of gallons with this.

 

[Brieninsac]

Add a few bottles of Bio-spira.