The SUMP SLOW DOWN: The benefits of slowing down the water?

[mfinn]

I keep a high flow inside the tank that keeps the detritus in suspension that goes to a slow flow in the sump where it can settle out.

 

[WaderJames1983!]

Do you all think low flow tbrough/in the sump could cause nitrate to be 80-100ppm? I have a 150 DT with 40 sump, I am running a good skimmer and algae upflow scrubber and my nitrates are this high...My source water is the ocean and its nitrates are nearly undetectable as is my RO top off. In tank flow is 3 mp40's. I am about to start dosing vodka, but would like a reasonable guess as to why my nitrates are off the charts before proceeding. An ATS with a skimmer ought to be enough. My only thought is the detris that settles on my sump floor because my slow return pump doesnt create enough flow to keep up with my overflow. Thus my overflow is dialed back quite abit.

 

[Dan_P]

Do you all think low flow tbrough/in the sump could cause nitrate to be 80-100ppm? I have a 150 DT with 40 sump, I am running a good skimmer and algae upflow scrubber and my nitrates are this high...My source water is the ocean and its nitrates are nearly undetectable as is my RO top off. In tank flow is 3 mp40's. I am about to start dosing vodka, but would like a reasonable guess as to why my nitrates are off the charts before proceeding. An ATS with a skimmer ought to be enough. My only thought is the detris that settles on my sump floor because my slow return pump doesnt create enough flow to keep up with my overflow. Thus my overflow is dialed back quite abit.

Except for something dying, the source of ammonia that is oxidized to nitrate is the food added to the aquarium. The ammonia is generated by the consumers of the food, including bacteria that eat the left overs.

The high steady state concentration of nitrate suggests that ammonia uptake rate by organisms and algae scrubber, denitrification rate, and rate of nitrate uptake by the algae scrubber, are too low.

Maybe the algae scubber is too small or not operating properly.

When did the nitrates become so high? Suddenly or over time? How much time? Did it coincide with adding stock to the aquarium? Ocean water might have low nitrate, but does it have a lot of microorganisms that die off when added to your aquarium?

 

[Chrille26]

When I had a refugium with Chaeto I thought slow flow was the way to go, but now when I only use mechanical filtation with skimmer and filter socks I think high turnover is better. Both to filter the water as many times as possible and also to not allow detritus to settle.
So right now I run my return pump almost at max plus I have a streamer in the sump keeping the water circulating.

 

[WaderJames1983!]

Except for something dying, the source of ammonia that is oxidized to nitrate is the food added to the aquarium. The ammonia is generated by the consumers of the food, including bacteria that eat the left overs.

The high steady state concentration of nitrate suggests that ammonia uptake rate by organisms and algae scrubber, denitrification rate, and rate of nitrate uptake by the algae scrubber, are too low.

Maybe the algae scubber is too small or not operating properly.

When did the nitrates become so high? Suddenly or over time? How much time? Did it coincide with adding stock to the aquarium? Ocean water might have low nitrate, but does it have a lot of microorganisms that die off when added to your aquarium

I had a pretty large lettuce sea slug get chopped up in my mp40. That was sad and of course could have been a cause of nitrate increase. I wasnt measuring them at first but instead watched for algae blooms and coral health. After adding several sps frags that turned brown and then pure white I started testing. Cal is 420, alk 10, po4 .05, and nitrate is 80ish. ATS is 7 1/2" by 7 1/2" lit on one side also have an aquamax skimmer rated for large bio load of 180gal. I feed flakes on an auto feeder 2x a day (roughly a pinch), a pinch of pellets, and occassionally mysis or nori. Again Display is 150gal, sump 40. I have 10 small blue green chromis, 3 tangs (small-medium), 4 wrasses, a small clown, a medium lawnmower blenny, a few snails, two star fish, and 3 sea cucumbers.

I'm not sure of die off of organisms from ocean water, but others use it with no issues. The last fish I intend to add are anthias. I also wondered if CO2 in my house being high could drive nitrates up...? Maybe adding a CO2 scrubber to my skimmer intake could help with gas exchange...I dont want to dose vodka, but I dont know what else could help. Thanks for any ideas.

 

[Lasse]

what´s your nitrites? (NO2)

What do you use to measure nitrate with (NO3) ?

I also wondered if CO2 in my house being high could drive nitrates up...? Maybe adding a CO2 scrubber to my skimmer intake could help with gas exchange.

No and no again

Sincerely Lasse

 

[WaderJames1983!]

what´s your nitrites? (NO2)

What do you use to measure nitrate with (NO3) ?

No and no again

Sincerely Lasse

I am using an api test for nitrate. I know its not the best, but I tested the ocean water and RO/Di to make sure the test wasnt faulty. They each tested near zero (yellow according to api kit) while my tank is deep red 80+. I have zoas, torchs, anemone, doing fine. My ATS has green thick algae. No other algae issues. Nitrite is not being tested. I assumed with good live rock, and clean sand my tank would cycle, have a few algae blooms and then be good in terms of nitrifying bacteria. Tank is 6 months old. Thanks

 

[MCWL]

I think both works sides have good points. If you have a high flow tank in the first place, then yes slowing the sump may be good. but if you already have a slow turn over tank, which is becoming recognized as viable now, then slowing down the sump may not be beneficial

 

[madweazl]

Do you all think low flow tbrough/in the sump could cause nitrate to be 80-100ppm? I have a 150 DT with 40 sump, I am running a good skimmer and algae upflow scrubber and my nitrates are this high...My source water is the ocean and its nitrates are nearly undetectable as is my RO top off. In tank flow is 3 mp40's. I am about to start dosing vodka, but would like a reasonable guess as to why my nitrates are off the charts before proceeding. An ATS with a skimmer ought to be enough. My only thought is the detris that settles on my sump floor because my slow return pump doesnt create enough flow to keep up with my overflow. Thus my overflow is dialed back quite abit.

Having tried many different flow rates through the sump over the years, I've never seen any difference. As for detritus build up, I've never seen it make a difference in nitrate levels either. Our 75g had 3 1/2 years of detritus in the sump before I tore it down and nitrates were always very low. I have cleaned the bottom of the sump on the 150g since it was setup 23 months ago and nitrates have remained the same in it.

What you're adding to the tank (i.e. food) is what is causing your elevated nitrates. You're introducing more than your setup is capable of removing. Now, your nitrification cycle may not be complete either; how long has the tank been setup? It may be that once truly complete, you'll be just fine or you may have to increase your uptake/export.

 

[Lasse]

I ask for the nitrite levels because of one very important reason - it interfere with the nitrate readings. A nitrate test is basically a nitrite test plus a metal salt that will convert nitrate into nitrite and the thest measure the produced nitrite and convert it over to nitrate (the colour scale) with a certain conversion factor. For most tests - the factor is 50. It means that if you have 0.1 in nitrite - it will give you 5 ppm extra nitrate in your readings. If you have 1 ppm in nitrite - you will read 50 ppm extra nitrate and so on. Before you do anything - get you a Tropic marine NO2/NO3 PRO test (not the one without pro in the name). With help of that you can determine your nitrite level and your nitrate level and compensate for the misreading caused by your nitrite level. Conversion factor for Tropic Marine NO2/NO3 PRO test is 100

Sincerely Lasse

 

[SPR1968]

In my new big tank, I’ve got a slow flow rate through the sump of just around 3 x per hour to increase contact time with the filtration systems, in particular a whole lot of Seachem Matrix, about 56 litres I think!

I can see the point in ‘whizzing water’ through the sump at a fast speed to be honest, but there are different ways of doing things.

My display circulation is a different thing altogether with MP60’s/40 creating lots of water movement for the corals and fish.

 

[WaderJames1983!]

I ask for the nitrite levels because of one very important reason - it interfere with the nitrate readings. A nitrate test is basically a nitrite test plus a metal salt that will convert nitrate into nitrite and the thest measure the produced nitrite and convert it over to nitrate (the colour scale) with a certain conversion factor. For most tests - the factor is 50. It means that if you have 0.1 in nitrite - it will give you 5 ppm extra nitrate in your readings. If you have 1 ppm in nitrite - you will read 50 ppm extra nitrate and so on. Before you do anything - get you a Tropic marine NO2/NO3 PRO test (not the one without pro in the name). With help of that you can determine your nitrite level and your nitrate level and compensate for the misreading caused by your nitrite level. Conversion factor for Tropic Marine NO2/NO3 PRO test is 100

Sincerely Lasse

Hey Lasse,

I got the tropic marine pro kit. My nitrates are still high. The kit goes up to 20ppm and you can dilute to get what it is when higher then that. So I went ahead and tested nitrite next. It was .2ppm which means 20ppm of my nitrate reading is actually nitrite. So I likely have high nitrites and some nitrates.

I am also on day 4 of vodka dosing...my concern is, why does my tank appear to not have enough bacteria to complete my nitrifying process? Its a 6 month old tank.

 

[Lasse]

why does my tank appear to not have enough bacteria to complete my nitrifying process? Its a 6 month old tank.

The right question in this case is - why have my tank not enough space for a healthy and large enough population of NOB (nitrite-oxidizing bacteria). The right answer will be that most space is already occupied by other type of bacteria - mostly heterotrophic bacteria. Your vodka dosing does not make the situation better - on the contrary - it benefit more heterotrophic bacteria. Your load of organic matter - other than DOC (dissolved organic carbon like vodka) can also be to large.

The way I would solve this if it was my tank is to install a internal foam filter with high capacity in the sump. My favorite in this class is this from EHEIM

​

The pores are rather rough (not fine) and the pump is powerful. You cane easily make a one by yourself with help of this type of foam and a power head. I use 10 ppi. High flow is important. If you have a huge organic load in the aquarium - rinse the filter foam passably once a week. (not to clean!)

​

I would also skip the vodka dosing till I got the NO2 int the 0.005 - 0,02 range. To use a good brand of mostly NOB bacteria like nitrospira, nitrobacter and other is a good additive also.

When everything is good but PO4 and NO3 needs to be adjusted - maybe time to unscrew the Vodka bottle once again, But use the internal filter and rinse it passably often.

Sincerely Lasse

 

[WaderJames1983!]

The right question in this case is - why have my tank not enough space for a healthy and large enough population of NOB (nitrite-oxidizing bacteria). The right answer will be that most space is already occupied by other type of bacteria - mostly heterotrophic bacteria. Your vodka dosing does not make the situation better - on the contrary - it benefit more heterotrophic bacteria. Your load of organic matter - other than DOC (dissolved organic carbon like vodka) can also be to large.

The way I would solve this if it was my tank is to install a internal foam filter with high capacity in the sump. My favorite in this class is this from EHEIM

​

The pores are rather rough (not fine) and the pump is powerful. You cane easily make a one by yourself with help of this type of foam and a power head. I use 10 ppi. High flow is important. If you have a huge organic load in the aquarium - rinse the filter foam passably once a week. (not to clean!)

​

I would also skip the vodka dosing till I got the NO2 int the 0.005 - 0,02 range. To use a good brand of mostly NOB bacteria like nitrospira, nitrobacter and other is a good additive also.

When everything is good but PO4 and NO3 needs to be adjusted - maybe time to unscrew the Vodka bottle once again, But use the internal filter and rinse it passably often.

Sincerely Lasse

Ok that makes sense. My thoughts are, could I add bio balls in my sump to accomplish the same. I have added an additional pump already to increase flow in sump. Or simply put foam in the path of the flow. Also would adding more live rock in my sump help instead of the above foam or bioball? My sump is a 40gallon rubbermaid with no baffles. So there is a good bit of space. Im trying to understand why one bacteria population is higher then the other. How adding a sponge works to increase the right bacteria. Perhaps it only works with the bacteria additive and a porus clean surface? Thanks again.

 

[Lasse]

A sponge will help with more space for bacteria to attach on. You should have a fast flow through it and rinse it rather often. With help of bioballs - it is possible to build a perfect nitrification filter if it is build the right way and that the flow of water continuous backflush the bioballs. Your vodka is energy for wrong type of bacteria. the (Bi)carbonates is energy for the NOBs Lesser organic carbon - lesser growth of heterotrophs that concour out the NOBs for space. If you add bioballs - high flow and not drowned. Please read this thread

Sincerely Lasse

 

[WaderJames1983!]

A sponge will help with more space for bacteria to attach on. You should have a fast flow through it and rinse it rather often. With help of bioballs - it is possible to build a perfect nitrification filter if it is build the right way and that the flow of water continuous backflush the bioballs. Your vodka is energy for wrong type of bacteria. the (Bi)carbonates is energy for the NOBs Lesser organic carbon - lesser growth of heterotrophs that concour out the NOBs for space. If you add bioballs - high flow and not drowned. Please read this thread

Sincerely Lasse

Thanks so much for the useful knowledge Lasse. Last set of questions...

1. Would live rock in my sump with good flow make it so I dont need to rinse media and still increase nitrifying bacteria?

2. I have a BRS gfo/carbon reactor with the gfo chamber not being used. Could putting bioballs in there (work)/keep debris from building up and thereby avoid nitrate issues down the road? Would this option be enough media to solve my problem..if so I can go buy bio balls today.

3. With the use of a filter sock would a sponge or bio balls need rinsed often?

Basically which option could work best? Thanks again