Truth about parameters.


New member
Hello all. I have been in and out of the hobby since the late 90s. I feel I have a very good understanding about methodologies and procedures, but lack confidence with certain topics.

For instance, there are several places, publications, forum posts, etc that post numbers for parameters. Ideally, you would like your tank to resemble these numbers as well, but at what expense?

I have a 155 that I have has since 99, and about a year ago had one fish. I went away to college prior to that, and slowly lost interest. Upon return, I wanted to get back into it. At one point my trates had to be in the 400. My crushed coral looked more like mud than anything, and my oh was around 7.5.

Rather than work with this mess, I decided to completely start over. I drained the tank, removed all sand, refilled tank with freshwater, bleached, and let it dry before recycling.

This was in august, and I have slowly added fish to where I am 5 months later. Right now I have a 7 inch blue angel, 4 inch asfur, 4 inch gray, 8 inch guinea fowl puffer, 5 inch green bird wrasse, 4 inch aussie tusk, 3 inch foxface, 7 inch sailfin tang, 3 inch achilles, 3 inch hippo, and a 6 inch volitan. I have a 300 gallon in my garage I am building a stand for, and will have tank up and running by summer.

With that said, my numbers are far from what I have read they should be. Before I say what they are , these Are tank specs:

155 gal, 20 more in the sump=175~
Weighed live rock dry: 115 lbs (started as dead Fiji and tonga)
1 inch reef grade sand on bottom,
Sro 3000 skimmer, bio pellet reactor using ecobak.
Two return pumps delivering about 1200 gallons an hour (6.8 turns an hour thru sump)

One maxspext rip tide (up to 5000 gallons hour, run half power)
I do one 30 gallon water change every ten days (17 percent)
I siphon half of the sand each water change. I use algae pad in back glass, magnet elsewhere. I have zero sponges in sump or
Over flows, and utilize one filter sock, ( not fine mesh, bleached and wash machined weekly)

As for feeding, I feed twice per day, spectrum pellets and seaweed in the am, and once at night mixing pe mysis, spirulina brine, krill and clams.
I also have a 25 watt uv that one return pump (mag 5, 250 gph after head)

My water is crystal clear, and there may be about a teaspoon of detritus laying in my sump at any given time.

Now the the params:

Temp: 78 f
Sg: 1.022
Am 0
Nitrite 0
Nitrate; blood red in API scale (>160)
Ph: sometimes 7.8, but typically 7.73 (pinpoint probe in sump)
Kh: 7 (7 drops in API kit turns water yellow)

My question is, if fish appear well and grand, doin start a different routine?

Do I start doing 30 percent changes, instead of 17?

What about ph, do I buff water daily to keep it higher? ( I only use r/o water, <10 tds)

If so , here's my problem logically:

My pinpoint meter is about 5 months old. If I look at it the wrong way, the numbers move. I can calibrate it today, and tomorrow it will be a few ticks off, how do I know the machine is consistent and not precise? Is it more important the number, is 7.73 constantly (stable) or 8.2 -8.0 intermittently?

With nitrates, I am using API test kit. Could it be the test is off, and I am concerned about an unreliable piece of testing?

At the end of the day, my kit shows high nitrates. However, lack of maintenance or care, although not quantified or tested, IMO are superb.
To a layman, my tank is super clean, it's these numbers that keep me up at night.

And to further exacerbate my dilemma , being a math person, I can't figure this out; if your tank is fed x amount a week; say 10 grams of food. This equates in he end to 10 nitrates a week ( just an example)

If your start at zero (new water) and at the end if a calendar week have 10 nitrates, well no problem, water change. 20 percent water change leaves you with 80 percent of original water (80 percent of 10= 8)

So beginning of week two, you have 8 nitrates, you add ten more thru feeding, now you have 8 + 10...18

Another 20 percent water change and you have 14 nitrates. Draw this equation on a graph and you are at a hundred in no time.

I understand live rock, deep in its core should remove nitrate, but in all my years in keeping tanks, I have yet to examine that, even when I had
90 gallon reef tank with 140 lbs of rock. Perhaps if you had a sump 10x your display water volume, there would be enough.

Perhaps the answer might be to do 20 percent water changes, and once every 8 weeks or so hit it with a 70 percent change?

Again in all my years of maintaining not just mine, but class room, friend and family tanks, these numbers just never made sense or ares up to me.

But then again, I am not sure the non lab grade equipment, or at least affordable stuff I use to test with is any real indication if I have a problem or not.

Sorry for the rant, I am typing on an iphone looking at my tank, how it it looks fine to me, debating if I should ditch the pellet reactor (snake oil?) and start outing vodka in my tank.


New member
From my understanding, nitrates are a lot worse for corals than for fishes. Some fish are pretty delicate but tangs aside your list looks fairly hardy (if way overstocked). As long as the skimmer is working fine and you don't plan on adding corals I wouldn't worry about nitrates *too* much.


New member
Ha I would agree, but the more reading I do, the more lost I become?

My biggest concern is, unless I'm doing 100 percent wc, ( open loop system?) the number of nitrates will neve balance, but continually climb..what will it be in 2 years?...6 years??...

I guess my whole initial thought is, when someone is my situation says there nitrates are 40..or ph is it really? Not that there lying, but misinformed on reliability of a test?


New member
There are all sorts of things you can do. I'm no expert, but I know there are a lot of additives and filter media out there that will absorb nitrates or specific other compounds, balance pH, etc. Depending on how obsessed you are it's easy to spend tens of hours and hundreds of dollars a month trying to maintain perfect water parameters.

Your nitrates will eventually stabilize at some level, it will just be astronomically high compared to that of someone who frets over a SPS reef tank.


Saltwater Addict
If your nitrates are high that can be directly linked back to a overstocked tank, over feeding, and not enough biological filtration. You could change 100% of the water every 10 days, you are always going to have nitrate problems because your filtration can't keep up with the bioload


New member
Dmorty- I repectully disagree, on the biological part, because I may just not no any better. I am trying to understand.

Nitrates are the end result of the cycle...and only specialized bacteria housed in low oxygen areas can remove them and has them out. I never get ammonia or nitrite readings, and up until a month ago checked them daily.

So in order for my bio filter to work on the nitrates, I need low 02 areas. If I add anymore rock in display, I might as wel have a rock tank. One can only see about 20 percent of my back wall in tank from the amount of rock I currently have. A dsb is another option, but from what I've read, dsbs are often more problematic then beneficial.

I could use a bio pellet reactor, but I am currently running one and have since the tank started, and still having issues.

Down stocking would certainly help, but I had this issue with just 5 fish. I am thinking about carbon dosing, but I really want to hone in on the use, and not just do blindly. I could also do 35 percent water changes, but long term that adds up quick.

I for the curiosity of it, brought my water a sample, along with my API nitrate kit to my lfs. I ran a test on my tank and his tank, simultaneously , using same procedure, mix up time, lighting etx, and same API kit.

Out colors were identical. So either my test is fraudulent, or high nitrates don't seem to be bothering our tanks. He has regal angels, emps, achilles tangs and pbts, since the summer time, that seem fine. Really doubting testing agents.

I also brought my ph meter, and my fish only read 7.80, while his sps tank read 7.99. Knowing that, I will no longer chase ph. I am fine being within 2 tenths of his sps tank ph vs my fish only system.

Again, I am twisting and spiraling this info to come up with a concluding. No disrespect or foul intended.


New member
160 ppm of nitrates is too high even for fish, in the mean time I would change out more water per week, possible 50% weekly until its under control. If you try vodka dosing with your nitrates that high you will probably get a bacteria bloom

I do agree you are low with the anaerobic bacteria. The shape of the live rock is more important than the amount. If the shape of the rock is smooth, and no nooks and crannies there will be very little anaerobic bacteria


Saltwater Addict
Do you have another tank you can hook to your system to just have it full of rock to possibly help? When my 220g was full of tangs and angels I fed between 5-8 times a day but never had nitrates show up from over feeding or fish waste. Some nitrates are fine and most fish except delicate ones should be unaffected. A bio pellet reactor would probably be most effective way besides water changes to remove the nitrates. How deep is the sand bed in the tank?


Saltwater Addict
You could also post this question in the reef chemistry forum. I'm sure you will get a lot more technical answers to your questions. Randy Holmes Farley knows his stuff and I'm sure could help you. I haven't ever done anything special in my tanks not to have nitrates, I guess I was lucky


Moderator, 10 & Over Club
Premium Member
Hobbyist grade test kits are good for ball park measurements. That said, for a fish only, at a maximum for Nitrates, I would recommend keeping those ball park readings at least on the test kit's scale. Many fish can handle high nitrates (though some do seem sensitive to them), however, if your readings are off the scale you have no way of knowing just how far off. With pH, I'd consider 7.8 a lower limit, with 8.0 or higher preferable.

As for trying to calculate how much feed = how much Nitrate input, just too many variables....variability in food N content, individual fishes metabolism, etc. You'd drive yourself batty, and never get it figured out with any reasonable idea.


New member
My sand bed is only 2 inches deep.

Four days ago I started dosing vinegar. I will see if that helps at all.


That is the best I am able to get, even with brand new water mixed up. My lfs, who has a very good reputation, let me use my monitor on his tanks. His sps tanks were 8.0 -8.1. His fish only tanks measured 7.56 in. In here he keeps everything from angels and tangs, to Pygmy angels and gobies. Of course in different tanks , but all the same system.


New member
The nitrates (and phosphates) in one of my 250 DT's were very high during the first 18 months my tank was set up. Unfortunately, I believe that condition led to a toxic dinoflagellate bloom. I tore the tank down and reassembled everything, and now am running a GFO and GAC reactor, as well as a biopellet reactor. My nitrates are in the 10ppm range, phosphates in the 5ppm range, and no sign of dino's.

Just my opinion, FWIW, but I am convinced that high nitrates are detrimental long term, and I have also become a GFO / GAC disciple.