Trouble understanding tank chemistry

[coreytreverson]

I have a 20 gallon that has been up for about 6 months and has had a lot of ups and downs as expected. Recently, the tank has seemed to stabilize. A couple days ago however, my large candy cane trumpets had one head not opening up. I figured something must’ve been bothering that individual head but I couldnt find anything. A few days later and none of the heads are opening. I’ve also noticed a large increase of filth in the tank including small amounts of gha and lots of diatoms and algae on the glass. I’ve also noticed a weird translucent membrane surrounding all my rockwork. Unfortunately I’m in college and all I can really afford for testing is the api kit. All my numbers have been healthy and stable except nitrate and phosphate which are both very low, potentially 0. It seems like whenever I try to bring these numbers up by feeding, the tank gets really dirty which doesn’t make sense to me considering how low the nutrients are. Is this still just new tank syndrome and something that will get better with time?

For context-
I was running carbon for about two months to help with a little cyano which is pretty much gone now. I stopped running the carbon just before these problems started and have since put more in to see if that fixes things.
I do water changes roughly every week and the tank will get very dirty the next day.
I just added a really small lawnmower blenny to help things and I’ve had a clown and peppermint shrimp as well as hermits and turbo snails.
all other corals are doing really well with the exception of a leptospirosis which I’ve had problems with since I got
sorry for the load of information just wanted to be very thorough and try to find a solution.

 

[blaxsun]

You'd need to provide a few more details such as the inhabitants, what you're running for filtration, your cleanup crew, etc. Also, without a full set of water parameters (salinity, alkalinity, calcium, magnesium, pH) and knowing what you have for lighting and flow - it will be really hard to troubleshoot anything with respect to the corals. If your nitrates and phosphates are at or near zero, things are potentially getting starved.

 

[mdb_talon]

When u say running carbon do you mean GAC or carbon dosing?

The translucent film you describe sounds like it could be bacterial outbreak...which can be made worse if carbon dosing.

 

[coreytreverson]

When u say running carbon do you mean GAC or carbon dosing?

The translucent film you describe sounds like it could be bacterial outbreak...which can be made worse if carbon dosing.

I’ve been using GAC. I attached a picture of the film which can be difficult to see. The I previously did a little research on that and read that it’s something caused by low nutrients and I forgot what it was called.

 

[coreytreverson]

You'd need to provide a few more details such as the inhabitants, what you're running for filtration, your cleanup crew, etc. Also, without a full set of water parameters (salinity, alkalinity, calcium, magnesium, pH) and knowing what you have for lighting and flow - it will be really hard to troubleshoot anything with respect to the corals. If your nitrates and phosphates are at or near zero, things are potentially getting starved.

I have a list of the inhabitants in the OP. My perimeters are
Calcium 380
DKH 8
Ph 8.3
Salinity 1.026
Unfortunately I cant test for mag. But I rely on water changes and everything else being stable and that’s worked fine up until now.

I feel that things could point to dinos and that would explain the low nutrients and quickly becoming dirty after a WC but it looks more like diatoms and algae to me.

this is the best picture I have right now because the lights are off (of what I believe to be diatoms)

 

[blaxsun]

I'd probably get an orange lip conch, some cerith or nassarius snails to help with the sand bed. I still can't offer much in the way other than general suggestions, as I don't know what size the tank is, if there are more than the 2 fish, how much you feed, filtration, lighting, flow, etc.