high nitrate problem

[hangles]

I everyone
I have been battling a nitrate problem for several months and cant seem to get a handle on it I have been doing large water changes sometimes half the water volume of my system and they keep coming back. I thought that once the algae died off that the tank would stabilize but it has not so where are the nitrates coming from ? I only feed once a day and have three fish and some softies and zoo's in a 75 gal with about 100 gal total in the system with a refugium any help or Idea's about this would be great!

Thanks Harold

 

[perenes]

do you have any macro algae in your fuge?
also is there any detbris on your sand bed or rock?

 

[hangles]

Running the usual cheeto and some long blade sea grass and nothing on the sand bed I clean it every time I do a water change

 

[ChrisKirkland]

What does your feeding look like? (as in how much and how frequent)

 

[fishfan09]

Not a pro by any means but I'll throw in a few things. What kind of water are you using? If you are using RODI it may be time for a membrane change, and if you are using tap switch to RODI water. Try feeding every other day once a day in small portions. Do you have enough water movement? How often are you doing water changes, and when doing water changes take a powerhead and blast your rock before siphoning and siphon your sand bed getting all the detritus you can. Like perenes said above add some macro algea to your sump (although this will not solve your problem on its own). Maybe you just need to beef up your clean up crew to keep up with the detritus? Good luck.

 

[A.VOID]

not sure from your signature. How much live rock do you have? 29 lbs in 75 gallons is not a lot.
What's your skimmer? How often are you emptying the collection cup? Have you tried running it wetter?
How long has the tank been set up?

 

[hangles]

wow! alot of questions here goes. tank has been set up for 4 years but has went through alot of changes I'm using a shallow sand bed now but before it was deep no nitrate problems then. I have plenty of macro algae in the fuge I just harvested half off it was full. I feed once a day a combo of home made and frozen variety's just enough that they eat all in a couple of minutes. new RODI filters. I have great water movement. clean up crew is a brittle star, nassarius snails Mexican turbo's, astrea snails, cerith and two emerald crabs. the skimmer is a ASM G-3 it has been modified to recirculate and has the gate valve also the skim is nice and thick right now. the live rock is a tad more more like 75lbs. I am doing water changes every week this last one was 45gal. Hope I answered everyone thanks.

Harold

 

[A.VOID]

Did you remove a bunch of sand? Go from the DSB -> current shallow

 

[hangles]

did that at the 2 and one half year mark

 

[kev2me]

Could it be the test kit giving you bad info? How old is it?

 

[CleveYank]

kev2me's test kit age/contaminated is good consideration.

If the nitrate test kit is sound, then
chances are good your phosphates are high as well.

Are you sure your RO/DI unit is putting out near -0- TDS?

How many inches total are the 3 fish in the 75? Add feeding with 3 fish totaling over 11 inches would be a marker that input into system will give you high nitrates and phosphates.

Any stray sunlight from windows hitting the tank?
This won't cause the nutrient, but it would help prolong an algae issue even with almost optimum water.

 

[hangles]

Ipicked up a salifert kit and it tells me my other kit is on the low side so I have a worse problem than befor the fish are two breeding clarkies laying eggs every 12 days and a yellow tang all total 8 to 9 inches. the TDS on my RODI is at 2 so thats ok and I do have so sunlight that gets to the tank but it is inderect. also I am running rowa phos in my reactor to combat phosphates.

is there anthing that takes nitrates out of the water these water changes are killing me going through buckets of salt like crazy!

thanks Harold

 

[CleveYank]

If you have a skimmer that has a true rating of 1.5 times your system volume and it can run to slightly wet? I'd recommend you consider giving Vodka Dosing a try.

Run a search on it for the threads.

 

[hangles]

thanks for your help everyone ! I have another idea that may be the problem and I want to shoot it past all of you. about the time this all started happening I turned down the water volume going to my skimmer it has the recirculating mod done and my return goes strait to it I turned the volume down thinking it would scrub the water more efficiently but maby its so slow that I have effectively turned my ASM G3 into A G1 or 2 . so is it possible to slow the intake of water to a skimmer enough to make it inefficient ? and if so is that why my nitrates are high ?

 

[jh2pizza]

I bet that its not the skimmer. Didnt the problem exist long before the skimmer was turned down?

 

[hangles]

Hi Joe
No the nitrate problem showed up after I dosed the tank with erythromycin to kill all the cyano. then two weeks later the nitrates showed up. up until then the tank had never had a nitrate problem. I was reading a thread about dosing sugar to boost new bacteria growth. and of course there is two sides to this all I want to do is reestablish the balance i once had.

Harold