Filtration Set Up - Help Sought

[FishFan_76]

Hello 
I am looking for some guidance on my Nano tank filtration. I will try to give as much info as possible. My set up is:

90 litre Nano tank with live rock - the only corals are some Mushrooms and a nice toadstool. The tank is several years running. First set up in 2009. 

Salinity is currently 34. My stocking is:
Pair common Clownfish 
1 Jade Wrasse
1 Regal Damsel 
2 turbo snails, 2 hermit crabs (1 red, 1 blue) 
1 Cleaner Shrimp 

I do not run a skimmer. There are 2 pumps - 1 high to move surface and the other at the bottom for bottom movement. Plus the external pump return flow which crosses the top surface flow. Do I need more flow? 

My filtration is a Fluval External 205 and this is where I seek guidance:

I currently have a phosphate issue which I am trying to correct with water changes, Seachem PhosGuard and reduced feeding (I am now rinsing frozen food with RO water and have changed my sinking food - as the one I was using I believe was adding to the phosphate). 

I use RO water and mix with Red Sea sat. 

Ammonia is 0, Nitrite 0 but Nitrate is high at 20>. I would like to reduce the Nitrate down somewhat. There is an algae issue and recently had a lot of Red Bubble Algae (unsure of name?). I manually removed them and cleaned the LR with RO water. I then get some red and green algae on the glass which I scrap off regularly. 

I feel the filter may be an issue. I have foam pads (4), then bottom tray is LR rubble, middle tray Fluval Clearmax x2 and top tray just introduced today Seachem PhosGuard. Normally I clean the pads every few weeks (I think this is another cause). 

Would it be an idea to change my media set up? I have read that people use floss instead of foam as the foam can harbour Nitrates. Do I need the rubble in there? If I removed the Foam all in one go would this affect the parameters negatively? 

Does anyone have any suggestions to improve my set up? Picture attached as well. 

Many thanks for reading. 

F

 

[plectastic]

I am new to SW but the first thing I learnt a while back not only online on here but also from my LFS was not to have foam media. I think that is your problem. They will be harboring nitrates. Everything else seems ok but I have limited knowledge so far. 

 

[Donya]

Have you had the nitrate reading confirmed by a LFS? Test kits can go bad sometimes and give strange, stubborn readings. 
 
Foam doesn't make nitrates. If not cleaned though, it will trap debris and uneaten food and keep it away from where the CUC would otherwise dispose of it - and then you will get excess nutrients. Any filtration media can do this, even rubble or in-tank LR stacks if not properly maintained. The difference with rubble is that it usually has some bugs living in/on it that act as a mini-CUC and it's easier for those bugs to keep it clean than is the case with densely packed foam. Foam needs to be manually cleaned (and thoroughly!) at least once a week in most cases to avoid this, unless it's being used as an in-tank prefilter where bugs and things can do that cleaning for you. If you have a lot of foam media, keep a watchful eye on ammonia and nitrite if/when you yank it out, since it will be helping you with those steps of filtration too. 
 
When you say red bubble algae, do you mean something like an actual algae (there are things that look like red versions of green bubble algae), or is it the slimy stuff that simply traps bubbles in it? If it is the slime, then that gets knocked away by high flow. If it's actual algae then flow may not make a difference. Either way, whatever it is will be acting as a nutrient sink, which means you'll have to either decease the nutrients going in or introduce an alternative nutrient export (Chaetomorpha works well) to fully solve the problem. It sounds like you might have already found the culprit of excess nutrients though, so that may be all you need to address.
 

I then get some red and green algae on the glass which I scrap off regularly.

Sounds like coralline algae. That's good! It's annoying to scrape off, but that's another thing that can help act as a nutrient sink when you beat back something like red slime.
 

I currently have a phosphate issue which I am trying to correct with water changes, Seachem PhosGuard and reduced feeding (I am now rinsing frozen food with RO water and have changed my sinking food - as the one I was using I believe was adding to the phosphate).

 
Cleaning frozen in water (I use a cup of tank water that I toss out afterwards) goes a long way to getting rid of excess nutrients. Be patient! It can take a long time for nutrient problems to resolve once you fix a problem at its source like this.