Help with Diatoms and red Cyano

[RGA]

Hi Everyone,

my tank has been up and running about 4 months now.

I have brown diatoms on the sand and a red algae (cyano) outbreak.

I thought I was doing everything right, but just dont seem to get on top of it.

I am cleaning my skimmer every day, and filter sock, changing my water (RODI) every week, and have got some chaeto for my fuge. It just wont go.

I checked my RODI and it tests zero for phosphates.

I am feeding every day 1 frozen cube of brine shrimp, and am thinking maybe it is either my lighting or feeding.

Help !

I do have a problem with my siphon, and dont think I have been siphoning up enough off the sand, but that doesnt explain the rocks still being covered in cyano.

I have got some chemiclean coming, but I really need to understand where the problem is coming from before I think of using it.

 

[nvladik]

First question is always: post all your parameters.

 

[ReefWreak]

As mentioned, need tank size, parameters, fish load, etc.

I think a cube a day is a lot of food for most people's tanks, considering that most people have <100g of tank water. What size tank and skimmer?

You could cut back on feeding, try adding GFO (Phosban, ROWAphos), blasting the cyano on the rocks with a powerhead to blow it away every few days, and/or try dosing a competing bacteria that often can help reduce cyano algae.

Chemiclean works, but it's best not to use an antibiotic if you don't have to, since it kills almost all bacteria, not just cyano, and there are parts of the ecological spectrum that will likely get killed inadvertently that are positive contributors, whether they be nitrobacters (nitrogen cycle) or just break down excess food in the tank.

 

[JammyBirch]

Please post your tank size, age and water parameters.

Diatoms are not your fault it happens so no worries, I had great luck with dwarf cerith snail crushing my diatoms in under a week, I got them from reef cleaners.com.

Cyano is a bacteria, lights out should take care of that. I had a reddish slimy looking layer build up in my sump I was sure it was cyano, lights out for ~3-4 days will wipe it out.

Please do not buy miracle chemicals 9 times out of 10 there is a better way then pouring in a solution. I've never used a chemical yet and never want to. Even for better growth, just seems like a risk to me.

 

[Doogy]

Like everyone is saying, we need to know your tank size, parameters, light cycle, inhabitants etc. Diatoms and cyano are pretty typical. What is your flow like, as far as power heads? Black out for 3 days, large water change and running gfo did the trick for my diatoms. Good luck!

 

[RussIV]

Hi Everyone,

my tank has been up and running about 4 months now.

I have brown diatoms on the sand and a red algae (cyano) outbreak.

I thought I was doing everything right, but just dont seem to get on top of it.

I am cleaning my skimmer every day, and filter sock, changing my water (RODI) every week, and have got some chaeto for my fuge. It just wont go.

I checked my RODI and it tests zero for phosphates.

I am feeding every day 1 frozen cube of brine shrimp, and am thinking maybe it is either my lighting or feeding.

Help !

I do have a problem with my siphon, and dont think I have been siphoning up enough off the sand, but that doesnt explain the rocks still being covered in cyano.

I have got some chemiclean coming, but I really need to understand where the problem is coming from before I think of using it.

use the chemiclean but realize usually you have an imbalance that needs to be fixed.
im guessing your nitrates are 0 as well.

get them higher than phosphates. preferably 2-5ppm. dose mb7 and stability for competing bacteria after the chemiclean has run it's course.

when your system is too clean, nothing will outcompete cyano. all it needs is carbon and light. and of course the mandatory 16:1 nitrate/po4 for photosynthesis.

if you keep trates around 2-5, and keep po4 below .1 you should be fine. but dont run gfo if you have 0. if you believe you have 0, turn it off. i wont turn my gfo on unless i see .06 ppm po4. nitrates will put enough pressure on suppressing po4 by itself.

anyway, i have limited info on your system so that is all i can add.

 

[RGA]

Tank stats

Tank stats

Thanks everyone. Apologies.

Tank is approx 450 litres, 100g, with sump, set up in main display DSB and plenum.
Salinity 1.025
Nitrates nil, running a phosban reactor and some carbon also.
Phosphates test nil on RODI water, but sometime can climb to .25ppm before water changes (weekly).
Has some issue with PH dropping to under 8, but watching this, probably due to keeping glass lid closed and temperature rising from usual 27 degrees to 28. Purchased a fan, and leaving lid open to help.

Stocked with Algae Blenny, 3 Lyretail Anthias and 2 common clowns.
Some CUC but looking to increase.

Is it an issue my nitrates being nil all the time then ?

 

[rt67ghy]

Your PO4 is the problem; you definitely need to get that under 0.1 ppm and keep it there using GFO. But don't let it fall below 0.04 ppm until you have more experience. WC by itself won't be enough to control PO4 nor will growing chaeto.

 

[markandamb]

Yes having a gfo reactor will do wonders!

 

[CStrickland]

I would keep an eye on the phos levels coming out of your phosban (gfo) reactor and change the media as soon as they start to creep up. I'm guessing it's just taking a little longer than usual for all of the silica and phos to leach out because you have a lot more fresh sand than most with the dsb / plenum. Also, idk a lot about it but I think they take a few months to really settle in and get populated.

A soft toothbrush can help free stuff off the rocks to suck it out, or you can let the cyano grow into bigger mats that pull free for easier suckage.

What do you have going for current in the tank, how many powerheads/gph?