please help very confused!!

[yellowlogi]

I have a alge problem. It looks like a dust all over my live rock. I have scrubbed it off with a toothbrush but i don't know if it looks like it is coming off and really isn't or if it just comes right back about an hour later. Okay so let me tell you what I know and see if you can help
I have a 100g tank. 2x 250w MH 4 x 55w Blue actinic 30gal sump protein skimmer (in sump) fluval 404 canister filter. closed loop system pluse 2 ph for flow. 175lbs live rock, 125lbs live sand. use a RO filter for water changes and instant ocean salt mix. all my fish are doing great. lost all my corals. the tank has been set up for about 9 months.
probley the day before this i went to the lfs and got somthing called metal gone that i put in my sump that is supposed to get rid of any metals in the water. oh almost forgot. I put 275 snails in today to try and help the the dusty looking alge.
i tested my water on 4/18/06 and it was:
pH:7.8
Ammonia:0ppm
Nitrite:0ppm
Nitrate:20ppm
Calcium:1000
Salt:1.016
sence then i have done water change or two
and on 4/22/06 it was
pH:8.0
Ammonia:0ppm
Nitrite:0ppm
Nitrate:20ppm
Calcium:400
Salt:1.0185
sence then did another water change or two
and today (4/27/06)
pH:7.8
Ammonia:0ppm
Nitrite:0ppm
Nitrate:30ppm
Calcium:360
Salt:1.020
what do i need to do to fix my tank? all of my corals have died. i didn't have very many but i still don't like them dying.
if you need to know anything else feel free to ask. thanks for any help you may have.

 

[yellowlogi]

i also cut feeding back to 1 every 3 days because i was feeding everyday and i thought that might be why my nitrate is so high

 

[yellowlogi]

any help????? Please?

 

[divetroop]

How long has the tank been set up?
What color is the algae?
What's your water temp?
PH- Should be at approx. 8.3-8.4
Salinity- 1.023-1.025
Personally, I would stay away from the metal removing chemicals. Have you tested for phosphates? You shouldn't have phosphates if you use RO water? The snails should help out a lot.

 

[toungetwster]

You have several problems. First your pH is low!! It should be 8.2 lower than 8.1 is bad higher is not good either. Also; your 100 gallon tank must be full of LR, sand and snails. with the quantities you listed in your post! Your trates are high because you are using a canister filter. With all the live rock and sand you have you shouldn't need a canister filter. How long has your tank been up? What fish do you have and what are the measurments of your tank?

 

[toungetwster]

Also; your salt levels are wayyyyyy low! Should be 33-35 ppm spacific gravity. What are you using to measure your salinity?

 

[scotts]

WHOA! I am by no means an expert, but looking at your salinity levels and your CA levels, you water has been bouncing around alot. I would think first of all you need to take out that metal gone stuff. If you are using RO water and the filters have been changed recently, you will not have metals in your water.
The let's look at your short sentence "lost all my corals" What type, how long ago and was it a fast demise or a slow one?
Scott

 

[yellowlogi]

ok to try and answer everyone questions on one post.
"How long has the tank been set up?"
9-10 months
"What color is the alge?"
greenish brown
"Whats your water temp"
80
"What fish do you have?"
diamond goby, yellow tang, baby blue tang, moron clown, foxface
"What are the measurments of your tank?"
5 foot long about 21 in tall and 18 wide
"What are you using to measure your salinity?"
Hydrometer
"Lose of corals, what type, how long ago and was it a fast demise or slow one"
I had a finger leather, pulsing xina, some mushrooms,
the xina went very fast the finger went slow and the mushrooms look like they may not be completly dead they are shrivaled up but you can still see them.

 

[toungetwster]

Pitch the hydrometer and get a refractometer! They are much more acurate. Maybe you need to look at the salt mix you are using. Do you test each batch before you add it to the sump? You need too! As someone said in this thread; your water is outta wack...salinity and Ca are all over the place along with pH. These 3 readings alone will kill your tank! The metals remover may very well have something to do with all the off levels in your tank as well.
My suggestion; 1. Set up a QT tank and transfer all remaining stock to it. 2. Pull the plug on your main tank and start over. TEST TEST TEST new water with the old LR let it cycle and go from there. This is what I would do; if I were in your position. Sorry...just my thoughts.

 

[yellowlogi]

bump

 

[dfox]

The folks above have covered a lot, but here are a couple more thoughts. If you don't want start over from scratch with the tank, you can try _slowly_ raising the salinity. Your salinity is too low right now. It should be in the 1.023-1.025 range. The way you do this is to use saltwater as your "top off" water. Or do _small_ water changes, perhaps 5% every few days with RO/DI water that you know is 1.025.
One of the common problems I have seen is that people don't test the water that they will be using for water changes, especially if they buy it from a local fish store. I have experienced this first hand. One container I bought had a salinity of barely 1.020. The next one was 1.025. That could be contributing to your flucuations in salinity over such a short timespan.
I would also recommend that you buy a KH test if you don't already have one. Your pH is going to fluctuate if you don't watch the balance between calcium and KH. The fact that you calcium was 1000 one day, and then 400 may be a factor in this. Do some searches on this message board relating to calcium KH balance. You'll see what I mean.
Hope this helps. Good luck!