Feeding 125G FOWLR and Nitrates question/dilemma

[ShirleyM]

First of all, our 120G reef is doing MUCH BETTER! Thanks for all the help along the way since last April or so...

Our 125G STILL has very high nitrates...100+. I had them down to 75 for awhile, but they are back up to 100+
Last night we made a big storm in the tank, scrubbed the LR up a little, and changed out 30 gallons of water. The water looks great, the tank looks fine, but the nitrates are still 100+.

There is no noticeable algae growing in this tank, and never has been.

20-gal sump, skimmer in sump works well, Genx mak4 return pump, one built-in overflow in corner of tank.

Plenum with 2" aragonite, fiberglass screen, then 2-3" aragonite. Medium size, not sugar size. It's full of LR, don't know the lbs, but there's plenty. Some has coralline, some looks "dead".

3-1/2 yrs old setup.

Inhabitants:
Very large Volatin Lionfish
large Redtail Trigger
medium Picasso Trigger
Medium-lg Naso Tang
Fiji Puffer (2-1/2"?)
1 medium b/w striped damsel that survived cycling and new fish
1 large Maroon Clown

All janitors, such as large snails, large crabs, etc get eaten by the fish, so maybe there's one or two large snails.

No fish have died in recent or even distant history, and these are all long-time inhabitants...had them since they were "little".

Available food: (they don't get all this every time or every day, but they've been fed every day...and getting groc. shrimp chunks every day)

Grocery store Shrimp
Live minnows on wkends - Lionfish and triggers love 'em
Formula 1 and 2
Julian Sprung Sea Veggies
frozen squid (San Fran Bay brand)
Selcon - rarely...maybe 1/wk or 1/2wks
Omega One Flakes
Mysis Shrimp - frozen

Now, what would you eliminate or add and how much/often would you feed if this were your tank??

I think the food is the cause of the high nitrates.

I also think water changes done more frequently would help -- up to now it's been about 15-20 gal change every now and then...sometimes 5-6 wks inbetween. (Water is RO and salt is IO. Salinity: 1.024. pH 7.9-8.1) What would you do?

Thanks in advance...I really want to get this under control and keep it that way!


Shirley

[Doug1]

Shirly, you have a tank full of pooping machines Between the waste and the amount of food the high readings arent unusual. I suspect without a good population of scavengers at the top end of the reduction process, alot of it is missing out on bio-reduction. I think this is a case that a huge HSA type skimmer would be appropriate, otherwise the options would be to esentially replace the water several times to dilute nitrates or add sump kind of algae filter to the mix, even a rubbermaid throw together would work.

[ShirleyM]

[pooping machines!] OK...you mean some sort of Rubbermaid refugium? I could do that if I could figure out how to get the water back and forth to the sump or tank...(I can read the previous posts about this when I decide to do it)

What feeding schedule would you recommend? how often, how much, which kind, eliminate any of these? And what sort of scavengers will survive with these predators??? They all get along beautifully, but add anything new and they dive in for a meal.

Is there room here for yet one more...such as an Angel? We've wanted one since the inception of this tank, but A) I won't add anything to this level of nitrates for fear of killing it, and B) perhaps there's no room as it is...

What's an HSA skimmer? (cost? height?)

If I took out all the rock, cleaned it real good, cleaned up the sand some more, A) would that help? B) would the nitrates just zoom back up again?

Space is a problem around this tank...

THANKS DOUG!
Shirley

[Doug1]

HSA= high speed areator, ie a beckett type with huge pump feeding it, (read BIG$$$$)
If you do the water change route, you will need to do large and lots as the dilution is not a direct percentage, plus the process of food/waste is not on hold
I think the algae export mechanism would maybe be best long term solution to keep nitrates down to a decent level

[ShirleyM]

OK...so if I get the nitrates down with something close to a tank overhaul would I be able to keep them down with less feeding and more water changes? How would you feed them?

Would a DSB work better than the plenum? They have dug a hole down to the screen to make a cave, so they'd probably have a field day with a DSB!

Thanks again for your time!
Shirley

[RJ]

My brother in law went thru this exact scenario at about the same timeframe as well....our theory after discussing many options was that overfeeding and lack of nutrient export was his problem...he ended up with red algae...big time...he figured lighting change would do it...nope...after removing all the rock many times and scrubbing....he added a cpr refugium....limited his feeding down to twice a week....and most importantly....he removed all the fish...for 2 months...and every week he did 30% water changes....and lowered his nitrates down to zero...with no fish in there to accumulate waste...the nitrates stayed there...the refugium helped with the nutrients...and he has since gone to full reef....moved all his coral and such from his small reef...and has been up and running with no problems...we theorize that over the years the nitrates/phosphate leeches into everything...rock...sand...water obviously....and without removing it just accumulates...hopefully this helps....RJ

[ShirleyM]

Thanks, RJ...
I've had occasional red algae slime on parts of the sand bed, and sometimes a little on the glass sides. It looks like there's a layer of that underneath a normal inch of sand, and about 1" or 1/2" deep at that point, then normal sand again - I can see it thru the glass in front.

As for moving the fish out...no place to put them and we already have the reef tank and want to keep this one as a FO tank.

I guess with large water changes and a refugium, that will be our best bet.

Feeding: Do you mean feeding 2 x wk total? These fish would probably eat US if we made them wait that long...however, if they will be healthy fed that infrequently, I'd do it. I'm wondering if they can get by on just flakes and the dried seaweed and leave out the shrimp and other mush stuff except of maybe 1/wk...???

Anyone else??

Thanks again,
Shirley

[RJ]

As an example in that tank he had a SnowFlake Moray that I originally had from about 3 inches in length...I was feeding him once a week....a few pieces of mussel of shrimp...that was 4+ years ago....he still has it...feeding once a week and it is now 9 inches long and at least 3 inches around...just because they will eat doesn't mean the "need" it....RJ

[ShirleyM]

Good point! I think these guys are overfed...

[Doug1]

Overfeeding would certainly aggrevate the builup problem. There may be some truth in the scenario of the LR and or plenum leaching nitrients back into the water column.
Think of the bio mechanism at work in a healthy system, you have the primary scavengers snails,crags,shrimp,stars etc eating left over food and some waste, then the pods, worms and such working on that , and on to the bacteria level. I think the figure used is about 8 levels of reduction between waste/food and conversion back to basic elements. I suspect that the chain in incomplete in this particular system, combined with high fishload, you are getting the reduction down to the nitrate phase but its being over whelmed from there.
A series of water changes combined with the addition of a efficient export mechanism should over time get the nitrates down to a more managable level, along with reduced feeding. I wouldnt add another fish at this point,FWIW

[ShirleyM]

Thanks, Doug!
We aren't planning any more fish at this point, definitely, and maybe never due to the nitrates! I hadn
t thought about starfish...maybe there is a starfish that would eat the leftovers and not be eaten by the fish...there aren't any corals in this tank except a few stray zoanthids, some encrusting star poyps, and a lobopytum leather that was transplanted from the reef.

Any starfish ideas??
Thanks,
Shirley

[Doug1]

maaybe a couple brittles after you get the nitrates under control

[ShirleyM]

OK, so the high nitrates will kill the brittle stars? I don't think I can get them down much, but I will be doing 30-gal water changes every 10 days or less, and hopefully that will help. I figured the starfish might help get them down, rather than just keep them down.

Thanks again,
Shirley

[Doug1]

I know echinaderms are sensitive to salinity parameters, dont know for sure but I suspect high nitrates would not be good

[ShirleyM]

OK, I'll do the water changes and change the feeding.

I fed them myself tonight - gave them tiny chunks of Formula 2, tiny chunks of mysis shrimp, a few Omega One flakes, and a clip of sea veggies. I only fed one chunk at a time, and then stopped flakes as soon as they slowed down. I also removed the leftover sea veggies and gave it to the other tank's tangs. They seemed quite satisfied with that, and only one small piece made it over the overflow and nothing hit the bottom...

I'll let you know when I get an improved nitrate reading, and THANKS A BUNCH for all your help today!!
Shirley