Nitrate HELP

[Codyheitmiller]

So I have been battling the nasty rusty orange algae and my lfs said my tank is cycling again and to not do any water changes... but my nitrate has stayed at 20 for two weeks and the tank sand is covered in the nasty algae and all my fish are starting to not eat.... should I do a water change? I have had my tank up for 5 years and never had this happen, even when it had it's first cycle... I need help guys and I can't send pictures... sorry.

 

[AquaRick]

Can you ID the algae from here?
ReefCleaners.org | Clean Up Crews and Macro Algae - Nuisance Algae ID Guide

How long has it been since your last water change? 2 weeks?

 

[Codyheitmiller]

Diatoms. and it's been about 3 weeks

 

[Codyheitmiller]

75g, dogface puffer, tabbaco basslet, and a niger trigger, the biggest is the basslet at about 7'' I have a aqua ero 180 skimmer, and a 20g sump/ref full of rock and cheato algae. some mangrove trees as well.

 

[AquaRick]

Diatoms are usually caused by silicates in your tank. Since yours has been running for 5 years is there something that you've changed to your tank recently? New water source, excess in iodine dosing?

 

[Codyheitmiller]

I took out some rocks and put them into a new tank, and got rid of my corals. thats about all

 

[Wy Renegade]

How many rocks did you remove? Removing the LR also removed the Anaerobic bacteria that lives deep inside the rock. These bacteria are the ones that are responsible for converting nitrate into harmless Nitrogen gas which then escapes the aquarium via the waters surface. By eliminating part of the population of these denitrifiers, you have trapped the excess nitrate in your tank, thus causing an algae bloom, as algae trive on nitrate. Replacing the removed rock with other "dead" rock will provide additional deep surface area for the denitrifiers to occupy.

 

[Codyheitmiller]

No more then 30lbs. Should I do a water change?

 

[AquaRick]

Strange if nothings been added. Either way, water changes will help with the diatoms as well as bring your nitrates down. Not sure why your LFS recommended you to stop your PWCs. Fish are still in there.

Diatoms should go away in time. A good CUC, circulation in your tank, and PWCs will help.

 

[Codyheitmiller]

I have two good power heads in there, my puffer will eat my CUC

 

[Wy Renegade]

30 pounds was probably close to 1/3 of your total LR volume in a 75gal tank? I would immediately do a PWC, and look into adding some more rock back into the tank.

 

[Codyheitmiller]

I had 150+ lbs of rock.

 

[Wy Renegade]

Hhhhmmm, my other thought then would be that you stirred up some debris from a dead zone when you removed the rock, and this is causing a mini cycle within your tank. I'd still do the PWC.

 

[Codyheitmiller]

Thanks guys

 

[AquaRick]

Hhhhmmm, my other thought then would be that you stirred up some debris from a dead zone when you removed the rock, and this is causing a mini cycle within your tank. I'd still do the PWC.

Yup. Something had to cause the silicates increase to start the diatom bloom.

 

[Codyheitmiller]

I'll keep it updated

 

[Codyheitmiller]

So I did my water change and the next day it turned into the dreaded red slime algae...