Diatoms In Well Established Tanks

[mattlee]

im currently running just 2 tanks at the minute that are well established but im getting diatoms......

the first tank is a 4ft 240L filtered by 2 x rena XP3's and kept at 27 degrees C. stocking is 6 x juvi ornatum cichlids, 1 x juvi ebjd and 10 x colombian tetras. substrate is play sand and decor is rocks and wood with a few anubas plants. i do 1 x 50% water change per week using seachem prime. this tank has been running for a couple of years with constant 0 readings for ammonia and nitrite with nitrates getting to about 20-40 between water changes. pH is about 7.8.
this tank gets bad diatoms all over. the tank gets lots of light as its in the conservatory, ive covered it up during the day recently after getting algae growth on the sand that looked like jelly.... this has now cleared but the diatoms wont

the second tank is my 6.5x2x2 with the stocking of 1 x fully grown oscar, 8 x arulius barbs, 1 x bgk, 3 x humbug cats and 1 x jaguar cat. water stats are the same as above and decpr is just rocks and wood. the tank is filtered by 2 x FX5's and is kept at 26 degrees C. water changes on this tank are 1 x 50% every 2 weeks with sometimes a 25% change inbetween. this tank has been running for roughly 9 months and again shows no signs of ammonia or nitrates etc.
on this tank it seeems to appear on the back wall and in the right corner, strange as it never appears in the left side, either sides or front glass.... this tank is in the garage so gets no day light what so ever and tank lights are on for 7 hours and during the day the garage is lit by a dim light.

both tanks get fed once a day.

now from what ive read and been told in the past diatoms is due to traces of ammonia like in new set ups etc but this is clearly not the case with my tanks as they have been up and running for some time!

i recently read that silicate levels in water can cause diatoms but ive never tested for this as i dont have the right kit to.

could it be the seachem prime? although ive been using this for a while now.

can any one help me please as its doing my head in my new tank will be coming on the 11th and the fish from the garage tank will be having it but in our lounge and i dont want diatoms to take hold in here as well....

 

[RadaR]

You are right. Light+ammonia will give diatoms very quickly. Just because your tank is mature and your test kit says "0", doesnt mean tiny concentrations of ammonia arent there. We are talking 2 to 3 orderes of magnitude lower than what can be registered on hobby grade test kit. Think about it. If your ammonia was truly "0", then you wouldn't get the end product of nitrate. The nitrogen cycle just wouldnt work.
Silicates can never cause diatoms. Diatoms can indeed use silicates once the diatoms have bloomed. But silicate is not needed by the spores to bloom, only light+ammonia.
Light is the biggest contributor out of the two (light+ammonia). Just have to work at reducing both or one of them.

 

[mattlee]

yeah sure without ammonia ther would be no nitrates i understand there must be tiny traces.

the tank in the conservatory has been covered during the day for a while and the lights are only on for 5 hours at the minute during night so no extra light is being used, ie day light. this is not to the liking of the anubas though.....

ive just read that adding phosphate remover to the filter will help. is this true?

i dont really want to do more water changes as i feel 50% is more than enough a week. but if it will help then i might have to.....

without plants the light source is just for viewing pleasure so maybe ill reduce that in the new tank and try feeding a bit less.

a lot of sites are saying about silicates being a cause and state that play sand contains this which is what i have also.

 

[RadaR]

Phosphates again are not the cause of the algae bloom.
The spores are only looking for ammonia and light and once they do, they will flagellate and bloom. Then, just like a plant, they can use nitrates, phosphates, silicates etc to grow.
These other sites are still probably in the old school method of thinking and probably think excess phosphates cause algae
You can opt for phosphate remover if you want. Understand though that you will only be taking away a nutrient which the algae can use to grow once bloomed. It will never get rid of the algae. You cant win and beat algae by limiting nutrients. They are way too advanced for that. But, like I said, feel free to give it a go.

 

[mattlee]

So would you suggest just less light and less food for a while instead?
With my lights only being on for 5 hours though would a total blackout be an idea, if so for how long?
It's so annoying.........

 

[StandbySetting]

One option that I've found to work is increasing the flow in the tank using circulation pumps, it will eliminate any pockets of ammonia that may be present due to poor circulation in some areas of the tank (namely the corners).

 

[Geoff-]

get siamese algae eaters. they'll help keep things clean.

 

[aaronnorth]

Silicates remain in the substrate for years, so if that was the case then we would get diatoms constantly!

Aaron

 

[walkers101]

get siamese algae eaters. they'll help keep things clean.

fighting the cause is better than helping to clear it

 

[Geoff-]

get siamese algae eaters. they'll help keep things clean.

fighting the cause is better than helping to clear it

You're right, I rescind my previous advice. Matt, the cause of your diatoms is clearly that you have a fish tank. Take the fish back to the LFS, drain your tank and sell it on ebay. That will definitely solve it and is better than promoting an ecosystem in which the fish naturally maintain your tank for you. Perish the thought!

 

[RadaR]

walkers is right.
Geoff, dont' be childish.

 

[mattlee]

 

[Geoff-]

walkers is right.
Geoff, dont' be childish.

Whatever. Matt's already trying less light and less food, to the point where his fish aren't enjoying it. 50% weekly changes too. That counts as fighting the cause in my book. Should he just continue doing that, to the detriment of his fish's health and his own enjoyment of the hobby?

SAEs won't cope with an out of control bloom on their own but they will help. Any algae that is eaten is algae that is a) gone from the tank and b) unable to cause more algae by reproducing. In the case where you are trying to get a bloom under control again they are studious helpers that will help you out.

I can tell my advice was just dismissed without any intelligent thought behind it, which is why I made my subsequent comment. SAEs help, in conjunction with what is already being done. Take it or leave it.

 

[StandbySetting]

Whether it's detrimental or not is quite debatable, fish in the wild get no way near as much food as they do in home aquaria, doing the steps recommended is a long term fix, it only needs to be done until the algae is gone, and then the aquarium conditions can be changed to ensure it doesn't come back.

Plus SAE's get incredibly big and will only eat algae when young, after this they'll turn to eating fish.

 

[mattlee]

im not too sure that SAE's will touch diatoms will they......?

not all algae eaters eat all types of algae and i thought that SAE's were best for bba types of algae not diatoms as they dont clean so to say like a plec does off the glass and decor.