Eliminating nitrates - water change frequency, bio balls, etc.

bearwithfish

well if you are looking for inexpensive and still a good pump i would get the King 220 pump from petco .. it runs $20 and can move 280 GPH.... (i think) i dont remember exact specs but i run one for my return and one for my closed loop and they are great pumps for a good price..... for others i would say any of the Maxi-jets these are great pumps and you can do a small mod to increase their flow....

Administrator

Hi guys,

In a week it will be two months since I added 75 lbs of dry rock to the tank. I had added about 40 lbs a month or so before that, so there is a total of 100 - 115 lbs of rock in the tank. My nitrates are still at ~15 ppm. There is just one small chromis, one small piece of xenia, two turbo snails, and a bunch of crabs in the tank.

I'm always reading about reefs with 0 nitrates. I've added all this rock, but it's been two months and they're still higher than I'd like even with just one fish the size of a quarter. What's it going to take to get them down to 0?

Has it just not been long enough yet for the bacteria to colonize in the rock, and I can expect to see my nitrates begin to fall in another month or two? Should I remove all of the rock from the sump and replace it with cheato and a grow light instead? Wouldn't that deprive the tank of the additional rock/surface area for denitrifying bacteria, though?

Thanks!

bearwithfish

well first i would ask if you are getting a lot of build up on the rock in the sump... if you are then i would say try to place it in the DT if you are able to.... if not then i would leave well enough alone and check a few other things 1st being your test kit.. take a sample and test it and then have some one else (LFS perhaps) test the same sample to see if your test kit is good. 2nd how is your skimmer working is it getting a lot of junk out or just a little or none at all? have you had any type of diatom bloom? even a minor one that the crabs cleaned up fast?
as for cheato i would add it any way as it is a good export device and is natural...

Administrator

Hi Brett,

No, it doesn't look like I'm getting a lot of build up on the rocks in the sump. It looks to me like they are clean rocks. What would I see if they did have build up on them?

Unfortunately there isn't any room left in the display tank for rock, so if I removed the rock from the sump I would have to take it out of the system altogether. Do you think I should remove the rock and replace it with cheato even though it would mean having less rock?

I'll order another nitrate test kit to compare the results, but I'm pretty sure the API test kit I have is good. How much nitrate are you detecting in your system these days?

The skimmer is producing some skimmate each day. I want to run it "wet" so that it can skim the most possible, but every time I adjust the valve on the air pump that feeds it, I always seem to cause it to stop producing anything. Would adding another protein skimmer to the system help?

I don't think I've had a diatom bloom, but I've been fighting off cyanobacteria. I've been trying to suck it out and even left the light off for a couple of days, but a few days later it's back in full force.

bearwithfish

i am interested as to what other will have to add to this .. but IMHO.. i would take out the rock and put in the Cheato...as for your skimmer i dont feel as though you can over skim and adding another or replacing the one in use with one larger certainly would not hurt....my test results from last week continue to be undetectable for nitrate...
far as i can tell you are doing everything right so far i am also currious as to the cause .. and more importantly the solution....

Pasfur

I wouldn't be concerned at all. Natural nitrate reduction can be very unpredictable, even with established deep sand bed systems. If you asked me to guess, I'd say that sometime over the course of 4 to 6 months you will notice a difference. But keep in mind, the denitrifying bacteria on live rock are passive, meaning that the water is not forced to flow through the rock. It isn't like a freshwater filtration system with forced water flow. Local denitrification related to the breakdown of organic waste is much more predictable, which is why you are no longer seeing your nitrate increase... even if they are not decreasing as rapid as we would have hoped.

Administrator

So you are also "living the dream", at least the zero nitrate dream.

So that's one vote for removing the rock from the sump and putting cheato there instead. Do you have cheato in your sump with a grow light, Brett? I recall you saying that you used to have rock in your sump. Did you see a significant difference in your nitrates after removing it?

I'll keep my fingers crossed that that's the case. I think you said not to expect a difference for 4 months initially, but patience has never been my strong suit (although building my tank back up and waiting to add fish has certainly exercised it).

I wish it were the case that the rock was at least keeping my nitrates from increasing, but I actually do see my nitrates increase if I don't perform water changes. It starts to creep closer to 20ppm (orange) on the API test kit if I don't bring it back down with a water change. I also have only a single chromis in the tank and barely feed it, as opposed to the tank full of fish I used to have, which is why my nitrates haven't been as high or risen as quickly.

I have cut up a silver sized and put it in the tank for the crabs to eat a few times, though. Is that a bad thing to do? If so, what should I be feeding them instead?

Do you agree with Brett that I should lose the rock in the sump and replace it with cheato and a grow light, Mark? Does anyone else?

Also, my tap water has tested 0 for nitrates and phosphates so I've been using it. Do you think it would help my "cause" more to get an RO/DI system, or a GFO/carbon reactor?

bearwithfish

yes i took the rock out (except for some rubble i am seeding for some one) and grow the cheato under a clamp on light with a 5500k cfl bulb from HD and it grows like wild fire LOL..... as for adding the silver sides i would only do that if you did not have any other things in the tank.. they are great scavengers and i have never fed mine with no ill effects.. the addition of those may well be the contributing factor in this mystery.....

Pasfur

For the most part Mike, these just aren't things that I would be worried about personally. Throwing a small slice of a silverside into the tank will contribute to waste, yes, but not to any real degree. The same can be said for tap water vs RO, if you are getting a zero nitrate reading from the tap, I personally wouldn't be concerned in a non-reef environment.

As far as cheato in the sump, it wouldn't hurt, so why not give it a try?

I keep a very simple approach to this hobby and try not to tinker much. Most of these things we are discussing will probably have very little impact on the long term success of the system.

Administrator

Thanks, guys. I think I'll take the rock out of the sump and give cheato and a grow light a try.

The tank is a reef tank, or at least it will be. So far there's some xenia in it, and plan to get more coral once I'm decreased my nitrates and beaten cyano.