Phosphates & algae

[dava6711]

Hi

I really need advice as I’m struggling!

I’ve got three 8ft foot tanks connected by a single 4ft sump. They’ve only been online for a month or so but are filtered by an established sand filter transferred from an old, established tank & a Schuran Jetskim skimmer.

There’s no live rock in any of the tanks, but they all have a thin substrate of coral sand.

Livestock consists of only three small fish (royal gramma, clownfish & Bangaii cardinal) & a corkscrew anemone, I feed the fish every other day.

My problem is algae & phosphate. I can nuke the phosphate using lanthanum chloride so it reads 0 or 1ppb on my Hanna HI736 meter, but the next day I can have a reading exceeding 21ppb?

I replaced my RO membrane a month ago, the pre filters are new and I changed the DI resin a few weeks ago. My freshwater reads 0TDS after being processed by my RO/DI unit.

Where on earth can this phosphate be coming from?

My tanks begin to have a decent covering of algae after 3 days & the sand beds start to get discoloured by the algae after two days so I know my readings aren’t entirely false and there’s definitely phosphate in there.

But where on Earth is it coming from?

Any input or advice will be greatly appreciated.

 

[mcgyvr]

Food and could certainly be bound up in the sand filter..

Phosphate is actually a beneficial nutrient...21ppb is really not a problem at all and a great level to maintain IMO..

Algea is very common in new setups.. And just takes some time to pass as the system matures

 

[dava6711]

Food and could certainly be bound up in the sand filter..

Phosphate is actually a beneficial nutrient...21ppb is really not a problem at all and a great level to maintain IMO..

Algea is very common in new setups.. And just takes some time to pass as the system matures

Really appreciate your reply.

The substrate in all of the tanks is new, they're not established sand beds at all.

The sand filter is very established, and it has a massive amount of flow going through it, the aragonite in there is violently thrown around so there's no chance of any detritus or uneaten food being trapped in there.

So you think I simply need to exercise some patience and let the sand beds mature?

It's how quickly the algae develops on the glass walls of the aquariums themselves that worries me, I have to wipe them clean pretty much everyday.

 

[mcgyvr]

I think its certainly possible that the established sand filter could be a source of phosphates..
It could be from food but thats a lot of water for such few fish and I suspect you arent feeding that much..
Could also just be variation in the test kit...most aren't too accurate even at ppm levels..

 

[ThRoewer]

Algae can grow just fine even in low nutrient systems. It's more a matter of available setting substrate. If there is a free spot that gets the right amount of light you will sooner or later have algae growing there.

Sent from my XT1254 using Tapatalk

 

[dava6711]

Algae can grow just fine even in low nutrient systems. It's more a matter of available setting substrate. If there is a free spot that gets the right amount of light you will sooner or later have algae growing there.

Sent from my XT1254 using Tapatalk

Thanks for the reply.

What do you mean by "œavailable setting substrate"?

All three of the tanks are shallow and partioned into smaller separate tanks (like a local fish store), each of partitioned tanks is lit by T5's, currently two over each, a daylight 6500k & a white/blue combination bulb.

 

[mcgyvr]

Sounds like a normal new system to me...

 

[bertoni]

The growth might diminish with time, although that is an unusual configuration. I'd probably wait a few weeks to see what happens, and maybe add a few herbivorous snails.

 

[dava6711]

The growth might diminish with time, although that is an unusual configuration. I'd probably wait a few weeks to see what happens, and maybe add a few herbivorous snails.

Thanks for your input Bertoni.

What's unusual about the configuration?

I was thinking about getting some snails & other herbivores as there isn't any form of clean up crew currently. I'll add them this week.

 

[bertoni]

Most systems have live rock, which can help with exporting fixed nitrogen.