Bad Brown Algae/Diatoms

[bigfatfish]

The SG in my tank has slowly been raised as I go marine - it is currently at 1.019/1.020 & the sump/skimmer get installed at next water change. I have suddenly started with brown algae, which I assume is diatoms. The glass needs cleaning three, or even four times a day! It comes off really easily with the magfloat & looks sort of dusty. There is a bloom/haze to the water too. The ammonia/nitrite are zero & nitrate 5-10. Still learning about marine water - what else should I be testing for now? Is this bloom normal, even though this is not a new tank - or maybe it is classed as new, because of the new SG? I have 2x T5 marine white lights & 2 marine blue. The lights are on for about 8 hrs daily. Can someone reassure me that this is something that will pass?! Or is there something else I should be doing?
Thanks

[RTR]

It does sound like diatom.

first, read the ref in the Library here:

library/water-filtration/brownalgaediatoms/

Then come back and ask for any clarifications or details you need.

[bigfatfish]

Thanks RTR. I think it must be diatoms. So, should I test for silicates, or is there nothing that can be done anyway so there is little point? Do you think the raise in SG kick started this bloom. I guess I should just continue as I have been & hope it doesn't last too long - although glass cleaning that many times daily, is a little tedious!

[RTR]

That is way too much work for me. Cleaning the glasses once week is a chore to me. I have too many tanks for that.

Call your utility and ask if they have readings on the soluble silicates in your water. To me those folks are best and most neglected public service employees around. They tend to really pleased when folks show interest in their product. If they have readings, note them down and post back.

If your water is high silicates, you really should have learned before. So there is a chance that it is marginal and the steady-state level in normal operation may be less of an issue. That too is common - it may be an all-new-water issue.

The good thing about silicates is that they cannot recycle in real time. Once soluble silicates are incorporated into diatom "shells", it is there locked in for geologic time. The glass itself likely dissolves faster than the cast-off diatom "shells". there is huge difference in 100% new water and even 50% partials in the diatom response they generate.

That would be a case for "Wait and see". Some areas do really need pretreatment of the water. I would not want to live in those areas myself.

[El Scorpio]

Tap water no matter where you go almost always has phosphates and silicates in it, and brown diatom algae *requires* silicates in order to grow. Getting away from phosphates and silicates is probably one of the main reasons for using reverse osmosis water in an aquarium. Brown algae is indifferent to the salinity of your water; as long as it has phosphates, silicates and light, it'll grow.

You can get silicate absorbing media to place in your filter to help remove the silicates, or just simply start using RO water for water changes.

[RTR]

Re-constituting water to useful mineral profiles from RO or RODI is a PITA and expensive. Only rarely do folks do enough post-RODI supplements to naintain fish long-term without much care and costs.

Pretreatment with phosphate/silicate absorbing resins is not free, but far simpler than reconstituting RODI. It is not good form to run these in any tank for long-term plant or fish upkeep or for plants or fish breeding. Phosphates are absolute requirements for both fish and plants. Soluble silicates are not. It is simpler and cheaper to replace one thing (phosphates) that everything (total required mineral species).

It is not true that phosphates and soluble silicates are universal in fresh water supplies. They are not.

[Mac Myers]

Get Some Olive Nerites and acclimate them to brackish over a few hours. 4 will clear the brown algae in 2-3 days.

[RTR]

Olive nerites are also a bit puffer resistant until you get to mature GSP size. They are pretty round and expose very little foot/flesh as they move around.

But then you do have nerite eggs on the glass instead of diatom alga. The nerite eggs are less obtrusive -just a few white balls here and there.

[JRC3]

The nerite eggs are less obtrusive -just a few white balls here and there.

I always described them as sesame seeds.