Bacteria/diatom bloom crashing nitrates

[TastyScrants]

Hello,

Recently upgraded from 150L to 250L.

Nitrate running around 8.3ppm for a year, PO4 at 0.1ppm

New sand was rinsed with tap water and caused PO4 to increase to 0.69ppm which has been gradually reducing with GFO.

Silicate introduced from tap water rinse of sand has caused what I think is a large diatom bloom.

As a result my nitrate levels have been gradually crashing down to 0ppm.

I’ve been dosing 2ppm a day of nitrate and it is still falling. I have more fish and feed heavy. I’ve turned my skimmer down to just aerate the water and I’ve disconnected my mechanical filtration.

What do I need to do to resolve the issue?

My biggest concern is I crash and get dinos

 

[CoralB]

First I wouldn’t have turned off your mechanical filtration , if anything shut off or take the cup off skimmer and let it overflow into the sump . Are you still running the power head for surface agitation ? Your phosphates can be reduced using a product from brightwell called phosphat-e . And far as the nitrates go add more fish which as you said will help . The diatoms will run their course . Water changes with salt water made with RODI water wouldn’t hurt . Keep checking and maintaining your nitrates from going to zero .

 

[Salty_Northerner]

Almost looks like a bacterial bloom from the water looking cloudy. I went through that same situation and ended up with a massive Dino outbreak. I just gave up and strip cleaned the system and did a 3 day cycle. Nitrates are stable 2-3 but I need to add Neophos daily. And As the above mentioned, keep your mechanical filtration going. Also change out socks, floss or whatever your using daily. Brightwell has some great products and I'd be checking them out.

What got me through the diatom/cyano was PNS Probio added every other day. Adding calcium nitrate and microbactor7 helped as well. Bactor 7 will strip the nitrates but will consume the diatoms as long as you dose calcium nitrate and test every day till it settles out. The Probio will out compete the bacteria as well, but its adding good bacteria. Best added soon as the lights come on as it loves to do its thing and remains active.