Why does it never end?

[cannonman]

I have a three year old 75 reef that always has problems with high nitrates and low alk/calcium. If I do an 10-14 gallon water change every few days (3-4 days!) the problems go away and everything thrives. If I do water changes every other week the water quality just goes on a continuous down hill slide. Now I have friends who have tanks my size that hardly ever do water changes and have no problems with trates... they say don't treat the trates problem but rather find out what is causing them... so help me figure out what is causing my constant high nitrates problem (40-80 ppm!) and why my alk levels drop like a rock constantly..
Stats: three year old 75 reef
Sump with protien skimmer rated for a 150 gal.
Temp 82
Lights Twin 250 MH with accintics and LED at night
High rate of flow with twin Seios 1100s (had to turn one off)
Salinity 1.026 steady
Nitrites 0
Phosphates haven't tested in a while... did have some last time
Nitrates always high 40-80ppm
Calcium 350-450
Alk 5.5 to 6.5 dKh!!!
MG 490
The Alk and CA stabalize at a decent amount if I add B-Ionic every other day but it doesn't seem like I should have to add it that frequently... or no?
3-4" Sand bed
150-200lbs live rock
Stock list, two yellow tailed damsels, one electric blue damsel, one clown, one small/medium yellow tang, two three striped damsels.
A fair number of snails
4-6 small hermits
Black cuke that is BIG
3 peppermint shrimp
1 CB shrimp
Tons of corals, zoos do great and spread fast, as do the polys. sps corals stunt and then die, Xenia not doing well, frogspawn is growing great, candy cane does well, yellow cup coral on the way out, cloves do OK.
Am I doomed to have to do 10 gallon water changes every other day for the rest of my life??? Should I get rid of some fish? I haven't cleaned my fre filter in the over flow box very often but now do that with every water change...perhaps that was the problem? I wanted to have an sps tank but until I can get the water to stay decent I'm not even going to try.
Opinions wanted.

 

[tizzo]

Let's troubleshoot.
first off, I like your friends, they gave you good advice. Find the cause.
Secondly, if you have "tons of corals" then it's pretty common to have to add the two part every day. Personally, to save money and time I started dripping kalk (for calcium) and using kent's superbuffer as my alk replacement.
Tell me your mag level is about a thousand off...
And finally trates. They are most commonly caused by 3 things. one, over crowding, which I do not think is the case in your tank.
two, over feeding, which is a possibility since you didn't mention your feeding habits
three, tap water
and four...did I say 3 things? I meant 4. and four...old raggedy nasty canister filter pads that need changed out or rinsed out.
Oh and five, OK forget the whole counting thing, but supplements or "liquid foods"...baaad thing to add.
So, first off, tell us what you add to your tank from a bottle a freever a can, whatever...
tell us what, when, how often, how many etc...

 

[cannonman]

My bad, I thought I had it all covered but:
The Mag level reads in the normal zone in the sailifert test kit I use, perhaps that's not the number but I thought it read up to 500 (ppm???) and mine was just below that.
Feeding habbits... one frozen cube of spurinula enriched mysis shrimp every other day and one small pinch of pellet food every other day (none of it makes it to the bottom...or even half way without being attacked by the fish)
I add a very small amount of cyclopeze (sp?) about twice a week. Sometimes I squirt the corals one at a time, sometimes I just add to the tank.
I have no canister filter. Just a sponge filter in the over flow box and a protien skimmer in the sump.
I have a kent R/O DI machine and use only that water for all my tank needs.
The only additives that I add at all now (for the last six months or so) is the two part B-Ionic, although I have not been consistant with it, I'm getting better at that though...(and thus my alk and ca levels are improving)
I don't use any liquid foods at all.
What else?

 

[tizzo]

Based on what you put I'm still kinda thinking food. I'll explin. even though your fish eat all of it, doesn't mean it's not pollutin g the water. It has to come out too.
A full cube every other day is a lot of food! and to add pellets and cyclop eeze on top of that...
wanna try some different feeding techniques.
third cube every other day. and don't panick, I only feed my fish about every 4 days. have for years. No deaths, no diseases.
the cyclops, maybe once a week, and target feed only! Turn off all the powerheads, pumps and anything else thar moves water and target feed them. Once a week is way more than they need!! Unless they are malnourished, like a rescue LPS or something. With good lighting, you can go without ever feeding most corals and they's be fine.
Most, not all. candy canes, frogspawns, brains, they all like to be spot fed, but even those... every couple of days is a lot!

 

[cannonman]

Hmmm.. I appreciate the feedback. I didn't think that I was over feeding but I must admit it has to be something... I will start cutting back on the feeding today and will only spot feed the corals once a week. I think that my sponge pre filter in the over flow box was getting REALLY dirty to and now that I plan on cleaning that with every water change that should help... I hope. I forgot to add before that I was also giving my tang a small piece of dried algae sheet every day....
again, thanks for your input... I will put it to work.. no pun intended.

 

[tizzo]

The dried algae sheet is fine as long as...
it doesn't break off and float all over the tank to find a spot to rot and you remove the leftovers each evening. Don't let the stuff stay overnight.