water change question ??

[new-2-the reef]

I just did another water change last night (10 gallons from my 55 gallon tank)
and today my test are as follows
after 7 weeks up and running....

ph -7.8
ammonia-0 ppm
nitrite-0 ppm
nitrate-

why is it that my ph level has gone down ,from previous test over the past couple of weeks with a reading of 8.2-8.4 now down to 7.8

and my nitrate is still up at 20 ppm thats four weeks straight now at this level ,after a few water changes ...does this mean it is still in its cycle? and will it ever come down or do I need to add something to get it down?

also I seem to have this stuff on the top of the water,it kinda looks like a spill of some sort when gas touches water or some other chemical...
it is not through out the tank just on the top of water does anyone know what this is???
thanks
Clint.

 

[Anonymous]

that's a bit low for ph. What's your Alkalinity at? I'd be more concerned if alkalinity was really low. Just keep dosing to raise both PH and Alk. I am more concerned about alkalinity over PH. Which test kit are you using again?

For nitrates, either you have something building up nitrate (filter sock, mechanical filter, dirty pumps, etc) or your skimmer isn't sufficient.

 

[new-2-the reef]

that's a bit low for ph. What's your Alkalinity at? I'd be more concerned if alkalinity was really low. Just keep dosing to raise both PH and Alk. I am more concerned about alkalinity over PH. Which test kit are you using again?

For nitrates, either you have something building up nitrate (filter sock, mechanical filter, dirty pumps, etc) or your skimmer isn't sufficient.

my test kit is salt water master kit from aquarium phamaceuticals
my alkalinity has not been tested

my skimmer is a corallife super skimmer for up to 65 gallon tank
and I am running a eheim cannister filter for added flow with just some foam cartridges,filter floss and a carbon filter thats it no ceramic filter media..
I have been clening this filter weekly ...with no real build up at all inside it yet

as for the skimmer I am emptying the cup daily ,so it seems to be doing its job??

again my tank has only been running for about 7 weeks now

should I add a raw shrimp perhaps or would that just start the cycle again
and kill the clean up crew I already have in there??

 

[Anonymous]

CO2 can lower the pH. Do you have good top surface movement? Gas exchange can only happen at the top level, so it could be a water motion issue.

 

[new-2-the reef]

CO2 can lower the pH. Do you have good top surface movement? Gas exchange can only happen at the top level, so it could be a water motion issue.

YA i HAVE A POWER HEAD AND A KORILIA AND MY RETURN from my cannister filter all on top of water stirring things up...

right now my main concern is getting this nitrate down
it has been 3 weeks now at 20 ppm
I was told that is the bare minimum it should get to anything above will be fatal ,I want it at ZERO !
lol

 

[metalac]

it could be that your filter is causing high nitrates. replace the filter or clean it good and then do a water change and see what happens. You'll notice that a lot of people here don't use filters precisely for that reason.

 

[Anonymous]

I had that same skimmer. Actually, I still have it tucked away somewhere. It pulls skim, but it's not a very good skimmer. I recommend getting a better skimmer.

 

[new-2-the reef]

it could be that your filter is causing high nitrates. replace the filter or clean it good and then do a water change and see what happens. You'll notice that a lot of people here don't use filters precisely for that reason.

i was told to keep the filter for flow

thats why I still have it running but I have got the foam filters and the filter floss along with the carbon inside so it does not just pump back all the crap it collects from tank and pump it right back into aquarium

I have got rid of the ceramic media inside of it ,that wah tI have been told is the cause of all the nitrate problems with the cannister filters

should I just run it empty ? for the valuable flow it provides?

or just with the filter floss and carbon?

im at a stand still with this

 

[metalac]

well i think it's all the decaying stuff that might cause high nitrates, so the filter with catch all that stuff, if I was you I'd get a skimmer and have a return pump without that filter. But try running it empty or not at all just to see where the high nitrates are coming from. Make sure you do a water change after you make this change.