Safe max water change percentage?

RBarth · Jul 12, 2022

Sooooo...unfortunately I've decided I have no other choice than to remove all the stuff in my tank to catch...a...well...yellow clown goby that has managed to take out 3 duncan colonies. Basterd!!!! Anyway, I'm pretty sure I'm gonna be taking out most of the water and yes I could just put it back in but I normally do 20% changes every week anyway so why not go a bit bigger. What's a safe amount???

Mr. Mojo Rising · Jul 12, 2022

I've done 90% water changes a few times.
The only unsafe amount IMO is 100% because then the fish and animals will be flapping on the sand

RBarth · Jul 12, 2022

Thank you! This $9 fish has cost me $400. I honestly might eat him

homer1475 · Jul 12, 2022

As long as parameters match(temp, salinity, alk, cal, mag) 100% or as close as possible to 100% is no issue.

Pntbll687 · Jul 12, 2022

You can change 90%+ without issue as long as parameters are matched.

Did you see him eating the duncan? Never heard of them eating anything ever before

RBarth · Jul 12, 2022

He would try and host them which kept them completely ticked and then I finally saw him nipping at the tentacles last night. Everyone he's hosted has eventually died.

homer1475 · Jul 12, 2022

Pntbll687 said:
Did you see him eating the duncan? Never heard of them eating anything ever before

Agreed 100%.

Only thing clown gobies are known for is laying eggs in acropora, and sucking the slime off them till death.

Never heard of one bothering LPS before, and I have owned several over the years. Only reason I don't still own one is there relatively short life spans(2 to 5 years tops).

Pntbll687 · Jul 12, 2022

RBarth said:
He would try and host them which kept them completely ticked and then I finally saw him nipping at the tentacles last night. Everyone he's hosted has eventually died.

So he was just perching on them and irritating them? Was he just constantly on the duncans?

I only ask because duncans are super hardy, I've had some close for a few weeks before reopening. This is the first time I've ever heard of a clown goby nipping a lps coral of any kind and I'm intrigued. You know if it is a wild caught or captive bred fish?

How long have you had the duncans? I would imagine the fish would have to be on the coral almost constantly for this to happen.

RBarth · Jul 12, 2022

He never leaves them. Ever. He has managed to rub every bit of green skin off of them. Ive had them since December and they have been bullet proof until him. Trust me, i dont want to have to take everything out to catch him but also dont wanna loose another coral for him. No idea of the origins of this guy.

homer1475 · Jul 12, 2022

The ducan hosting the goby is not why the coral is dying. Highly unlikely cause of the corals death. Even in your picture, you can see the coral is wide open with the fish laying in the polyps.

Irritating it perhaps, but as with any coral croucher, the coral gets used to it and does not cause it's demise.

I honestly would be looking at different things for the corals demise.

RBarth · Jul 12, 2022

He's rarely on top and normally around the stalks. Ok, help me figure this out. Got him 6 weeks ago. He goes immediately to the first colony and that's dead within a month. I remove it and he goes to the other colony...now that thing is on its way out. I'm not saying it's 100% him but that's the ONLY thing that's changed. So I'm just assuming it's him???

Tonycass12 · Jul 12, 2022

homer1475 said:
The ducan hosting the goby is not why the coral is dying. Highly unlikely cause of the corals death. Even in your picture, you can see the coral is wide open with the fish laying in the polyps.

Irritating it perhaps, but as with any coral croucher, the coral gets used to it and does not cause it's demise.

I honestly would be looking at different things for the corals demise.

I agree w this. My clown goby has never caused an issue and is always in my acro colonies.

Tonycass12 · Jul 12, 2022

RBarth said:
He's rarely on top and normally around the stalks. Ok, help me figure this out. Got him 6 weeks ago. He goes immediately to the first colony and that's dead within a month. I remove it and he goes to the other colony...now that thing is on its way out. I'm not saying it's 100% him but that's the ONLY thing that's changed. So I'm just assuming it's him???

Could you put the Duncan thats left into an acclimation box or something similar just to keep the fish away for a bit. Might help you say for sure if he's the culprit.

homer1475 · Jul 12, 2022

RBarth said:
He's rarely on top and normally around the stalks. Ok, help me figure this out. Got him 6 weeks ago. He goes immediately to the first colony and that's dead within a month. I remove it and he goes to the other colony...now that thing is on its way out. I'm not saying it's 100% him but that's the ONLY thing that's changed. So I'm just assuming it's him???

Why do you think the colony is on it's way out?

In the pictures you've posted the colony looks happy, and healthy?

Pntbll687 · Jul 12, 2022

RBarth said:
He never leaves them. Ever. He has managed to rub every bit of green skin off of them. Ive had them since December and they have been bullet proof until him. Trust me, i dont want to have to take everything out to catch him but also dont wanna loose another coral for him. No idea of the origins of this guy.

Have you tried rearranging the coral? Could be a more simple fix

If you have to catch him. If you're lights are tunable, turn them on all red leds, and then slowly use a net to catch him. Fish have a really hard time seeing the net with the red on.