Frequent Asked Questions | D-D The Aquarium Solution


I am having problem with my new reactor. At first I had the issue with the pump being too powerful for the phosphate remover so I followed the instructions to T off the water to make it less powerful. This works although it quickly gets an airlock and stop and just pumps out the second outlet of the T. The pump is fully submerged in the sump and I am completely stumped as to how the air is getting in to cause this.

Do you know any solutions to this issue.

Many thanks


I recently purchased 3 x Hydra 26HDs from XXXXXXXX, 
. 2 were off the shelf and a 3rd was ordered for me. However it would 
appear that they are slightly different. The 3rd light has deeper Royal Blue 
LEDs - a couple of shades darker. Also I have noticed that when speed playing 
through the schedule the 3rd light does not join in and remains all LEDs off. 
The schedule appears to work fine on all 3 but occasionally I do get a red 
exclamation mark against the 3rd light which does come and go. I don't have 
them connected to my home WiFi the signal is not strong enough - I have them 
connected together using the AIFi - Is there anything I can do this and about 
the Royal Blue LEDs on the other 2 lights ? Thanks and Regards


I have an old deltec 1355 protein skimmer that has recently started humming really loudly.

Can you advise why this might be and what I can do to fix it?

Kind regards

I recently purchased al hydra 52 hd lights for my tank. I have it programmed for 8 hours of light during the day. Once the lights go off one blinks green and the other one is a steady blue. How do I get rid of this problem before I put my fish in the tank?

Thank You,


Hi guys trying to set up the Luna cycle and moonlighting on my 
new toy

Good morning,
I purchased last February 2 Hydra 52 HD lights from my local fish shop in 
Glasgow for my 7ft reef tank. I knew 2 lights would not be enough but due to 
unforeseen circumstances I could not get a third right away. Anyway I then 
bought a further light in the summer last year but I have only just set the 
third light up and there is a remarkable different in the blue led colour. 
The older 2 lights are more Iight blue and the new one is a deeper almost 
violet colour. When all three lights are on together the difference to my 
eyes is noticeable across the entire tank. Would you happen to know if the 
LED bulbs were changed in manufacture during this period?
Just makes the tank look a little odd later in the day when the blues become 
more in play.
Any help with this would be greatly appreciated.
Many thanks

Hi, I've been cycling a new tank and recorded a result of 1 on the salivert 
phosphate test kit. I added some rowa phos and this has come down to 0.5. 
This has been over a few weeks.

Do you think that this is now exhausted and i need to add a new 100ml? Can i 
just put the entire tub in?

I have a 95litre tank. All other readings are normal ammonia and nitrite are 
0, nitrate is 5. PH 8.2, alkalinity 8, salinity 1.025.

Many thanks for your help

Please can you tell me what is the macimum thickness of glass the protein skimmer 
will fit. I have a Juwel Rio 400 tank. It has a slight rim. Will this protein skimmer 
fit on it.
Many thanks


I have 3 Hydra 26 lights & have recently had to switch them off as I had to do a 3 day blackout as I am battling Dinoflagellates. I have now switched them back on & I have some problems: On the AI Quick Start Guide the label states Wi-Fi Network is on 6CF6(this is my middle light) & was the parent(green) - the outside 2 being the children. Since switching them back on my left light(6CFC) is the parent(although the light blinks green all the time) & my centre light(6CF6) & right light(6CFE) are the children(solid blue). When I go onto the AI app on my Android it says "Stand Alone" whereas before I'm sure it was "Cloud". I have set the lights for my normal schedule but with only Blue on & at 3% - they ramped down at 7PM(as per schedule) & went off at 8PM(as per schedule). 6CFC was still blinking green this morning. I have tried resetting the network settings/factory defaults as per "Button Functions" in the Quick Start Guide. Also can you advise of the fans at the top are on all the time(as they weren't when I reconnected my lights) or do they only come on when the unit gets hot(with only 3% Blue on for 90mins last night maybe the units didn't get hot enough?) These were purchased from my LFS circa Nov 2015.
Any help advice greatly appreciated. :)



Hello Tony,

I have seen a lot of helpful posts on the ultimate reef forum which I seem to be spending a bit too much time on!

I have bought a good few DD items through my LFS and this week a dd750 chiller for my rs reefer350 - believe it or not even now temp of the tank is creeping up because we have a lot of glass at the back of our house so i know I need a chiller.

I have bought a return pump and assume i need nothing else but some eheim green tube but have you any experience of where I'm best placing things - I'm using the standard sump that came with the tank so I have 2 or 3 chambers I could take water from and return water to - what's your recommendation as it doesn't appear to say in the instructions one place is better than another?

Chiller will be located in the right hand side of the cabinet as I am not able to situate elsewhere or nest to the tank so it's a very short run from sump to chiller and back.

I'm new to marine and am 2 months in so am going to put a thread up.

Thank you


Hi Stuart
Currently spending some time on the DD 900 and am wondering if the weir Combe is sitting right in the holder as seems lower that the housing. Should the Combe be higher to run at the same level as the housing or simply pushed down as shown?


How to remove the quartz sleeve and clean it? I cant seem to figure it out,.


Dear Sir/Mdm,

How are you?  I have been using the above for 3 years.  Recently i discovered that the waste collected in the cup is not more than 1/2 inch or so and will remain at this level for weeks even though is heavily stock with fishes.

Washed the cup and same result, 1/2 inch of waste collected.  So i thought is time to strip and waste the entire skimmer and it is still the same, no matter how i adjust the water adjustment.  It used to run beautifully for the past years and i have to empty the cup at least once a week.

Skimmer sits in the sump at about 22cm and air valve is set to max for the past 3 years. 

Hope u can advice the issue here?  Thanks!


I have a tropical cichlid aquarium (330ltr) but have an issue with high 
phosphates, the water in my area is high in phosphates, At the moment I put 
rowa in one of my external filters which controls it ok but I was wondering 
if you have a reactor which would be free standing and fit under aquarium 
with pump also under my tank. Also am I best to use rowa or bio pellets?




I have been reading through some of the FAQ and responses with regards to the 
Hydra 52 lights settings and I am conscious that these settings are dependent 
on a number of factors so I am hoping for some advice for my settings, since 
I am unsure if my current set up is doing more harm than good.

My tank is an AquaOne 68cm x 68cm x 68cm cube, 275 litres. I have a single 
Hydra 52 mounted 12 inches from the water surface with a controller, not a 
Director, although I am considering purchasing one.

My parameters are: Salt 1.025, Ammonia 0, Nitrites 0, Phos indictable, Mg, 
1350-1390, KH 9.0, Calc 450. I am struggling with nitrates at the moment, 
they are between 20-50ppm so I am using NO POX and have increased my 
biological filtration.

My corals consist of a lot of Torches, some Zoas, Xenias and I have a Bubble 
Tip Anemone. I have also got a Montipora which has bleached, which is the 
second one that has done this in a matter of a couple of months. Now this may 
have been due to a phosphate spike I had recently, and maybe the high 
nitrates but I cannot be sure.

I am not seeing much growth in my tank at all apart from the Xenias, it has 
been up and running for almost a year now and I am not confident in my light 
settings.I like my tank running very blue and my current settings are: White 
40%, Violet 75%, Red 5%, Green 5%, Blue 95%, D Blue 95%, UV 75%. Lights come 
on at 2:30pm with a 2 hour ramp time and shut off at 10:30pm after a 2 hour 
ramp time.

I want to have more growth whilst seeing the colours. Any help would be 
greatly appreciated, I am at a complete loss and have no idea what is best.

Thanks in advance.