Green hair algae on sand and fish dying

[Nromano1212]

Hello everyone. I was looking for some advice on my tank...

Ok so about 2 months ago everything was absolutely fine. My tank is roughly 9 months old. I've bought a few things from the local fish store and also got a few things from the sand bar. I had a hermit crab in there that ate my star fish, shrimp and I'm assuming my missing clown and possibly some blue leg crabs? He was in the tank for about two months without incident. I removed him from the tank and all of a sudden my sand started growing spots of green hair algae. I was thinking because the crab had a field day eating everything including a whole 3" star fish that it caused a major phosphate boost in the tank. It's a 400 gallon system with only a few coral frags (those are doing great) and only 11 fish with the biggest no bigger than 3" long. After that I did a major water change about 35%. There was also a 9 degree temp swing in the tank that stressed out and killed my blue hippo tang which I removed right away. I thought from that point the algae would clear up. My light cycle stayed the same too. To my surprise it got much worse. It seems like it was only on one side of the tank that isn't being shadowed by the rocks and has direct light. I don't have a gfo reactor yet but I'm wondering why this happened. I really don't know where to go from here? After the water change I waited until the next day for all the water to mix and used my Hanna checker and got a reading of 35. I know that's not good either so I'm just looking for some advice of where to turn next. I tried removing as much of the algae manually as I could. Do you think maybe I just need to add some more blue legs? I haven't added any since the original clean up crew. What is their normal life cycle? Do you think maybe I just need to add more of those? I'm planning on going tomorrow morning to buy 50 or so anyways. Thanks in advance for the help.

 

[George_Goosen]

Hello everyone. I was looking for some advice on my tank...

Ok so about 2 months ago everything was absolutely fine. My tank is roughly 9 months old. I've bought a few things from the local fish store and also got a few things from the sand bar. I had a hermit crab in there that ate my star fish, shrimp and I'm assuming my missing clown and possibly some blue leg crabs? He was in the tank for about two months without incident. I removed him from the tank and all of a sudden my sand started growing spots of green hair algae. I was thinking because the crab had a field day eating everything including a whole 3" star fish that it caused a major phosphate boost in the tank. It's a 400 gallon system with only a few coral frags (those are doing great) and only 11 fish with the biggest no bigger than 3" long. After that I did a major water change about 35%. There was also a 9 degree temp swing in the tank that stressed out and killed my blue hippo tang which I removed right away. I thought from that point the algae would clear up. My light cycle stayed the same too. To my surprise it got much worse. It seems like it was only on one side of the tank that isn't being shadowed by the rocks and has direct light. I don't have a gfo reactor yet but I'm wondering why this happened. I really don't know where to go from here? After the water change I waited until the next day for all the water to mix and used my Hanna checker and got a reading of 35. I know that's not good either so I'm just looking for some advice of where to turn next. I tried removing as much of the algae manually as I could. Do you think maybe I just need to add some more blue legs? I haven't added any since the original clean up crew. What is their normal life cycle? Do you think maybe I just need to add more of those? I'm planning on going tomorrow morning to buy 50 or so anyways. Thanks in advance for the help.

Your phosphates are at 35? Or 0.35? How did you test them?

GHA is always linked to GHA, and the fix for it is to fix the source of the problem.

Usually this is attributed to added nutrients that are not being exported, like via feeding as an example

 

[Nromano1212]

The Hanna checker read 35. I forget the proper equation to convert it

 

[CStrickland]

I use this Beananimal table for the conversion so I don't make a math error

It could be that the animals dying spike nutrients for the algae. Or your hermits were burying waste in the sand. Or the sand has gotten saturated with decayed waste and there's enough built up to grow algae. A lot of things can cause algae on their own or as a combination of little issues.
It might help to post a pic of your tank and explain what you are doing to remove nutrients from the system, like maintenance and filtration etc. If you want to find the source of the issue.

 

[Nromano1212]

Ok I'll post some pics up tomorrow but now that you mentioned that, I disrupted the sand prior to all this. The crabs digging it brought a lot of bigger shells and bigger pieces of rock to the top of the sand and I wanted a cleaner look. Also i pushed down the front sand against the glass to clean it so it looked nicer at the front of the tank. Do you think that may be where my problem lies?

 

[Nromano1212]

cStrictland.... The 35ppm doesn't seem like an overwhelming amount of phosphates? I mean it's not that low but it's not that high. I guess that was right after a decent size water change too though. I wonder what it was before?

 

[Kidd Reef]

Hello everyone. I was looking for some advice on my tank...

Ok so about 2 months ago everything was absolutely fine. My tank is roughly 9 months old. I've bought a few things from the local fish store and also got a few things from the sand bar. I had a hermit crab in there that ate my star fish, shrimp and I'm assuming my missing clown and possibly some blue leg crabs? He was in the tank for about two months without incident. I removed him from the tank and all of a sudden my sand started growing spots of green hair algae. I was thinking because the crab had a field day eating everything including a whole 3" star fish that it caused a major phosphate boost in the tank. It's a 400 gallon system with only a few coral frags (those are doing great) and only 11 fish with the biggest no bigger than 3" long. After that I did a major water change about 35%. There was also a 9 degree temp swing in the tank that stressed out and killed my blue hippo tang which I removed right away. I thought from that point the algae would clear up. My light cycle stayed the same too. To my surprise it got much worse. It seems like it was only on one side of the tank that isn't being shadowed by the rocks and has direct light. I don't have a gfo reactor yet but I'm wondering why this happened. I really don't know where to go from here? After the water change I waited until the next day for all the water to mix and used my Hanna checker and got a reading of 35. I know that's not good either so I'm just looking for some advice of where to turn next. I tried removing as much of the algae manually as I could. Do you think maybe I just need to add some more blue legs? I haven't added any since the original clean up crew. What is their normal life cycle? Do you think maybe I just need to add more of those? I'm planning on going tomorrow morning to buy 50 or so anyways. Thanks in advance for the help.

do you quarantine the stuff that you get from the sand bar? im not saying it has anything to do with your issues just genuinely curious. i live in florida so i've considered grabbing some native fauna myself but i've heard horror stories of hobbyists grabbing handfuls of what appeared to be red leg hermits from the wild and putting them in their tanks only to find out months later they were not reef safe.

 

[CStrickland]

cStrictland.... The 35ppm doesn't seem like an overwhelming amount of phosphates? I mean it's not that low but it's not that high. I guess that was right after a decent size water change too though. I wonder what it was before?

No you don't have crazy high phos in your water column. Fwiw that's all the gfo can reach anyway, the only phos it removes is the phos in the water that goes through the reactor. That's why I was thinking it might be more about dirty sand. Also, stirring it up a little shouldn't cause a big problem like that either. So I was thinking there's a basic problem with you adding more nutrients than you are removing but the hermits and buffering capacity of he rocks and sand were able to keep it just this side of the tipping point, until a few fish died and you lost the crab and starfish so it got pushed over the edge.

 

[splix]

Are you not heating your water change new water before you dump it in?

 

[A1t2o]

Are you not heating your water change new water before you dump it in?

If the water you are using for water changes is not the same salinity and same temp as the water in your tank then you are going to be causing more problems than you are solving by shocking the system that much. What do you have for water movement? Do you have a skimmer? Was there a temp spike or dip? All of these are factors, but it could be something else entirely too. Did you add anything recently? Oh, and where are you getting your water for the water changes from? If you are pulling if from the ocean then you could be screwing yourself over with the contaminates or bacteria you are putting in your tank.

 

[Nromano1212]

I get the water off shore from my boat. I actually think my salinity may have caused the death of my tang. I've never really had a prob with evaporation before but for some reason my water was really high. I checked this after the face of my yellow tang got really white. I added some r/o water and now he's looking a lot better. I've been really busy lately with work and stuff and been not really paying attention to all the details. I need to start paying closer attention to what I'm doing. Ugh.

 

[A1t2o]

I get the water off shore from my boat. I actually think my salinity may have caused the death of my tang. I've never really had a prob with evaporation before but for some reason my water was really high. I checked this after the face of my yellow tang got really white. I added some r/o water and now he's looking a lot better. I've been really busy lately with work and stuff and been not really paying attention to all the details. I need to start paying closer attention to what I'm doing. Ugh.

I would really recommend making your own saltwater. You never know what you are adding if you take it from the ocean (except for traces of gas and oil from your boat since you will always have that if you are drawing the water from your boat). Also, never top off your tank with salt water. Use RO/DI only for topping off or you will just be adding more and more salt as the water evaporates. Stability is key in the reef hobby. A sudden change in the salinity, temp, PH, and other things can cause your tank to crash more then having any one or more of those off will. You need to bring it back to the right parameters slowly, not all at once.