Repeated bacterial bloom in invert QT

[PotatoPig]

I’m running a small 5g invert QT tank and for a couple weeks now have been having constant bacterial blooms so severe I can’t even see halfway through the depth of the tank, which doesn’t seem to be doing the crabs any favors.

I’ve been doing 90% water changes to clear it, but keeps coming back regardless of whether I add any nutrients to the tank.

Any ideas on cause or cure for this?

Photo just after water change, everything now covered in stringy bacterial mess…. Including the crabs and snails. About the only things that seem unaffected are a thriving amphipod population.

 

[KrisReef]

Maybe try Microbacter7?
Or get a small UV

 

[TangerineSpeedo]

Yes, the little green killing machine UV. You can do Petco and get 30% off your first online order or something like that. That being said, what is your nutrient levels? On a small tank you do not have a lot of wiggle room, you have to run a much tighter ship!

 

[vetteguy53081]

I’m running a small 5g invert QT tank and for a couple weeks now have been having constant bacterial blooms so severe I can’t even see halfway through the depth of the tank, which doesn’t seem to be doing the crabs any favors.

I’ve been doing 90% water changes to clear it, but keeps coming back regardless of whether I add any nutrients to the tank.

Any ideas on cause or cure for this?

Photo just after water change, everything now covered in stringy bacterial mess…. Including the crabs and snails. About the only things that seem unaffected are a thriving amphipod population.

Part of issue is your filter. You need to raise water level and additionally you may be lacking filtration as your power filter is a mechanical unit which polishes water however you want to have mechanical , biological and chemical to manage proper water quality. The aquaclear will polish water and trap particles via the cartridge.
Chemical is what traps and breaks down chemical compounds such as feces and uneaten food often accomplished carbon and GFO
Biological is what utilizes the natural process of biological filtration such as use of ceramic nuggets, bio blocks, and microscopic bacteria surfaces as examples. Best it to add or use a hang on refugium such as Reef octopus or AquaMaxx unit and even add a hang on skimmer such as ice cap K1- or K2 100
Ammonia spike may have been very possible and often undetectable after the spike event.
When a sudden increase in the number of bacterial colonies generates and becomes suspended in the water column, it grows so quickly that it becomes more visible causing the water to become milky and hazy in appearance due to an increase in the nutrients in the water especially nitrates and phosphates. These colonies need to be reduced and eliminated.

 

[Dan_P]

I’m running a small 5g invert QT tank and for a couple weeks now have been having constant bacterial blooms so severe I can’t even see halfway through the depth of the tank, which doesn’t seem to be doing the crabs any favors.

I’ve been doing 90% water changes to clear it, but keeps coming back regardless of whether I add any nutrients to the tank.

Any ideas on cause or cure for this?

Photo just after water change, everything now covered in stringy bacterial mess…. Including the crabs and snails. About the only things that seem unaffected are a thriving amphipod population.

Bacteria blooms need a high concentration of “food” to form. Review how much you are putting into the aquarium.

 

[Jay Hemdal Verified Community Expert]

Agree with @Dan P , the bacteria is feeding on something. The large population of amphipods you noted is related to too much food as well.

There could also be a lack of good mechanical filtration in the HOB filter that is allowing the excess bacteria to circulate.

Jay

 

[PotatoPig]

Thank you all. I’m still a little stumped about where the nutrients are coming from as the latest bloom happened after my last water change (~90%) but without me adding any food to the tank, but agree that the growth of amphipods indicates there’s nutrients somewhere, and only food before then was live algae on a rock from my DT sump. Will see how this last water change goes, and look at a bigger (10g) tank and more robust equipment going forward.

Part of issue is your filter. You need to raise water level and additionally you may be lacking filtration as your power filter is a mechanical unit which polishes water however you want to have mechanical , biological and chemical to manage proper water quality.

For this, out of curiosity why does the water level impact the filter? I’ve been using the drop from the filter to generate flow, surface agitation and aeration, but didn’t realize it might be hobbling the little filter.

 

[Jay Hemdal Verified Community Expert]

Thank you all. I’m still a little stumped about where the nutrients are coming from as the latest bloom happened after my last water change (~90%) but without me adding any food to the tank, but agree that the growth of amphipods indicates there’s nutrients somewhere, and only food before then was live algae on a rock from my DT sump. Will see how this last water change goes, and look at a bigger (10g) tank and more robust equipment going forward.



For this, out of curiosity why does the water level impact the filter? I’ve been using the drop from the filter to generate flow, surface agitation and aeration, but didn’t realize it might be hobbling the little filter.

Personally, in tanks without air stones, I like to have a good drop for the water returning from the HOB.
Jay

 

[blkhawk10]

I'm curious if you ever solved this issue? I'm going through the same thing in my tank right now.

 

[PotatoPig]

I'm curious if you ever solved this issue? I'm going through the same thing in my tank right now.

Kinda. Resolved but not solved.

Never worked out where the nutrients were coming from - did three 90% water changes without feeding the tank and it was still clouding up.

Then was at the LFS and they had a couple pieces of live rock I liked with sponges, dusters, etc on them. I added them in and the next morning the water was crystal clear.