# What is this?



## Posie (7 Mar 2019)

Tank has been set up 5-6 weeks. Co2 injection and fertiliser with Tropica light. 50% water change weekly. PH 7.6 before CO2 starts in the morning. It's only really affecting my hair grasses. I have 2 little ottos and some shrimp in there now but they don’t seem interested in eating it. Ottos have done a great job on the other algae.


----------



## dw1305 (7 Mar 2019)

Hi all,





Posie said:


> It's only really affecting my hair grasses. I have 2 little ottos and some shrimp in there now but they don’t seem interested in eating it.


They are the filamentous diatoms formerly known as _Synedra,  _now more correctly_ Fragilaria_ spp.

I think Amano shrimps don't (or should?) eat it, I'm not sure about Cherry shrimps or _Otocinclus. _It is common in <"recently set up tanks">.

If you look at the colour you can see they are a browny green, this is because Diatoms have <"photosynthetic pigments in addition to chlorophyll">. If it was a green hair algae (like _Rhizoclonium),_ it would be more "grass" green.

We don't know exactly what stimulates its growth, bu tit may be associated with a build up of organic debris (often in the filter).

If you have a lot of media in your filter (or haven't cleaned the filter since set-up?) it might be worth taking some media  out, and particularly any that impedes flow, like floss or fine sponge.

I have an easy clean pre-filter to stop any organic debris ending up in the filter itself.

cheers Darrel


----------



## Posie (7 Mar 2019)

Thanks Darrell. I’ll try that. I haven’t cleaned it since set up. I’ll give it a go.


----------



## dw1305 (7 Mar 2019)

Hi all,





Posie said:


> I haven’t cleaned it since set up. I’ll give it a go.


Give it a clean and see what happens. 

The manufacturers media set ups for canister filters are usually intended for "fish only" set ups and have a lot more filter media than we (or they) need. 

<"Plant/microbe" bio-filtration"> is much more effective than "microbe only" filtration. 

People who don't keep planted tanks often regard plants as just another form of decoration, but they aren't they are the single most important factor in maintaining water quality. 

cheers Darrel


----------



## Posie (7 Mar 2019)

I read something about filter medium causing it by adding silicates. I have Biohome which is made from scinteted glass. I have ordered som Seachem Matrix to see whether that makes a difference. If I leave the coarse sponge in my filter will it be safe to chuck out and replace all the Biohome?


----------



## dw1305 (7 Mar 2019)

Hi all,





Posie said:


> I read something about filter medium causing it by adding silicates.


Just an internet myth, and another way for unscrupulous companies to part us from our money. There is always enough soluble silica for diatom growth, and the amount of it in solution has nothing to do with glass or quartz (silicon dioxide (SIO2)) sand, they are totally insoluble.

Have a look at <"Diatoms....">.





Posie said:


> I have Biohome which is made from scinteted glass.


Biohome is fine, the person who sells it has made all sorts of fairly laughable claims about "effective pore space", but it works the same as any other sintered glass media. Have a look at <"Biological media....">.

We have a <"Matrix thread as well"> , again nothing wrong with it, but nothing special about it either. 





Posie said:


> If I leave the coarse sponge in my filter will it be safe to chuck out and replace all the Biohome?


I usually have a mix of sintered glass and coarse sponge, but it probably doesn't make any difference. Some people have <"dish washing scrunchies and toy soldiers"> in their filters. 

This is the important bit 





ceg4048 said:


> Plants quickly uptake NH3/NH4 as nutrition, so we really don't need all that specialty stuff. The higher the plant mass the more thoroughly the job is done - and they pump Oxygen back into the water and sediment, which supports a more efficient bacterial load, so who cares if someone is selling overpriced special magic media with a gazillion square meters of surface area? That has no advantage whatsoever. A fish only tank is a different story because there is no method of NH3/NH4 removal other than the filter media.
> 
> So hobbyists coming from a fish only background worry needlessly about the wrong things. Put lots of plants in the tank and do all the things that foster _their _health. They, in turn, will make the tank healthier.


cheers Darrel


----------



## Oldguy (8 Mar 2019)

Posie said:


> I have 2 little ottos and some shrimp in there now but they don’t seem interested in eating it


Welcome to the Green Side. Clean up crews never clean up the stuff you want them to do (actually they do but can get overwhelmed). Ottos & shrimps do better in groups of at least six. It gives them more confidence. You know when things are right - tank spotless and you have to feed the clean up critters.

@dw1305 has put up some very good links, and made as ever, some very good points.

New tanks are always need to settle down and you have some very nice, but picky plants, could be worth adding some easy stem plants just till the tank matures. Hygrophila polysperma, especially the type with white veins and pink tinged leaves could be worth considering, even keeping. I find it is a useful indicator plant of general tank conditions. See threads on 'duckweed' plants. Some of us use Test Kits others Look at our Plants.  

Fire fighting: with your water changes will the filamentous diatoms vac out. 6% H2O2 applied topically will kill most lower 'plants'.

Fingers crossed for you.


----------

